diff --git a/README.md b/README.md
index 1ab1b13..306e3b9 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ By leveraging ZK Regex, developers can securely verify the presence of specific
 1. Start by providing a raw or parsed (expanded) regex pattern, then execute the following command:
 
    ```sh
-   npm run zk-regex '<input>'
+   npm run zk-regex '<regexPattern>'
    ```
 
    **NOTE:** `countEnabled` and `substringEnabled` arguments are set to **false** by default.
@@ -23,7 +23,7 @@ By leveraging ZK Regex, developers can securely verify the presence of specific
 2. In your TypeScript file, import the necessary modules at the top:
 
    ```typescript
-   import { Field, Bool } from 'o1js';
+   import { Field, Bool, UInt8 } from 'o1js';
    ```
 
 3. Add the function body and paste your specific ZK Regex circuit code.
@@ -115,6 +115,12 @@ npm run testw # watch mode
 npm run coverage
 ```
 
+## How to run zkApp example
+
+```sh
+npm run zkapp
+```
+
 ## Raw Regex Syntax Guide
 
 - **Alteration:** The | character can be used to denote alternation between two expressions. For example: A|B.
@@ -182,6 +188,8 @@ For more details, you can visit this amazing [ZK Regex Tools](https://zkregex.co
 
 - A huge thanks to the [zkemail](https://github.com/zkemail) team for their magnificent work on the original [zk-regex](https://github.com/zkemail/zk-regex), which inspired and aided in the development of this project. Their reference materials and documentation were invaluable in understanding the technical intricacies.
 
+- Special thanks to [Gregor Mitscha-Baude](https://twitter.com/mitschabaude) for identifying the inefficiency in processing full field elements. This change significantly improved the efficiency of the o1js-regex circuits.
+
 ## License
 
 [Apache-2.0](LICENSE)
diff --git a/images/alpha-low-zk-regex.png b/images/alpha-low-zk-regex.png
index e5bf2d6..3012d44 100644
Binary files a/images/alpha-low-zk-regex.png and b/images/alpha-low-zk-regex.png differ
diff --git a/src/examples.ts b/src/examples.ts
index ede205c..fa156ab 100644
--- a/src/examples.ts
+++ b/src/examples.ts
@@ -1,4 +1,4 @@
-import { Bool, Field } from 'o1js';
+import { Bool, Field, UInt8 } from 'o1js';
 
 export { 
         simpleRegex, 
@@ -8,8 +8,8 @@ export {
         negateRegex,
 }
 
-// "1=(a|b) (2=(b|c)+ )+d" & revealing ['(a|b)', '(b|c)', 'd']
-function simpleRegex(input: Field[]) {
+// "1=(a|b) (2=(b|c)+ )+d" & revealing ["(a|b)", "(b|c)", "d"]
+function simpleRegex(input: UInt8[]) {
         const num_bytes = input.length;
         let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
         let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -20,27 +20,27 @@ function simpleRegex(input: Field[]) {
         }
 
         for (let i = 0; i < num_bytes; i++) {
-                const eq0 = input[i].equals(49);
+                const eq0 = input[i].value.equals(49);
                 const and0 = states[i][0].and(eq0);
                 states[i+1][1] = and0;
                 state_changed[i] = state_changed[i].or(states[i+1][1]);
-                const eq1 = input[i].equals(61);
+                const eq1 = input[i].value.equals(61);
                 const and1 = states[i][1].and(eq1);
                 states[i+1][2] = and1;
                 state_changed[i] = state_changed[i].or(states[i+1][2]);
-                const eq2 = input[i].equals(97);
-                const eq3 = input[i].equals(98);
+                const eq2 = input[i].value.equals(97);
+                const eq3 = input[i].value.equals(98);
                 let multi_or0 = Bool(false);
                 multi_or0 = multi_or0.or(eq2);
                 multi_or0 = multi_or0.or(eq3);
                 const and2 = states[i][2].and(multi_or0);
                 states[i+1][3] = and2;
                 state_changed[i] = state_changed[i].or(states[i+1][3]);
-                const eq4 = input[i].equals(32);
+                const eq4 = input[i].value.equals(32);
                 const and3 = states[i][3].and(eq4);
                 states[i+1][4] = and3;
                 state_changed[i] = state_changed[i].or(states[i+1][4]);
-                const eq5 = input[i].equals(50);
+                const eq5 = input[i].value.equals(50);
                 const and4 = states[i][4].and(eq5);
                 const and5 = states[i][8].and(eq5);
                 let multi_or1 = Bool(false);
@@ -51,7 +51,7 @@ function simpleRegex(input: Field[]) {
                 const and6 = states[i][5].and(eq1);
                 states[i+1][6] = and6;
                 state_changed[i] = state_changed[i].or(states[i+1][6]);
-                const eq6 = input[i].equals(99);
+                const eq6 = input[i].value.equals(99);
                 let multi_or2 = Bool(false);
                 multi_or2 = multi_or2.or(eq3);
                 multi_or2 = multi_or2.or(eq6);
@@ -65,7 +65,7 @@ function simpleRegex(input: Field[]) {
                 const and9 = states[i][7].and(eq4);
                 states[i+1][8] = and9;
                 state_changed[i] = state_changed[i].or(states[i+1][8]);
-                const eq7 = input[i].equals(100);
+                const eq7 = input[i].value.equals(100);
                 const and10 = states[i][8].and(eq7);
                 states[i+1][9] = and10;
                 state_changed[i] = state_changed[i].or(states[i+1][9]);
@@ -76,7 +76,6 @@ function simpleRegex(input: Field[]) {
         for (let i = 0; i <= num_bytes; i++) {
                 final_state_result = final_state_result.or(states[i][9]);
         }
-
         const out = final_state_result;
 
         const msg_bytes = num_bytes - 1;
@@ -98,7 +97,7 @@ function simpleRegex(input: Field[]) {
                 is_substr0[i][0] = Bool(false);
                 is_substr0[i][1] = is_substr0[i][0].or(states[i+1][2].and(states[i+2][3]));
                 is_reveal0[i] = is_substr0[i][1].and(is_consecutive[i][1]);
-                reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+                reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
         }
         reveal.push(reveal0);
 
@@ -111,7 +110,7 @@ function simpleRegex(input: Field[]) {
                 is_substr1[i][1] = is_substr1[i][0].or(states[i+1][6].and(states[i+2][7]));
                 is_substr1[i][2] = is_substr1[i][1].or(states[i+1][7].and(states[i+2][7]));
                 is_reveal1[i] = is_substr1[i][2].and(is_consecutive[i][1]);
-                reveal1[i] = input[i+1].mul(is_reveal1[i].toField());
+                reveal1[i] = input[i+1].value.mul(is_reveal1[i].toField());
         }
         reveal.push(reveal1);
 
@@ -123,16 +122,16 @@ function simpleRegex(input: Field[]) {
                 is_substr2[i][0] = Bool(false);
                 is_substr2[i][1] = is_substr2[i][0].or(states[i+1][8].and(states[i+2][9]));
                 is_reveal2[i] = is_substr2[i][1].and(is_consecutive[i][1]);
-                reveal2[i] = input[i+1].mul(is_reveal2[i].toField());
+                reveal2[i] = input[i+1].value.mul(is_reveal2[i].toField());
         }
         reveal.push(reveal2);
 
         return { out, reveal };
 }
 
-// "([a-zA-Z0-9._%-=]+@[a-zA-Z0-9-]+.[a-z]+)" & revealing ['[a-zA-Z0-9._%-=]', '[a-zA-Z0-9-]', '[a-z]']
+// "([a-zA-Z0-9._%-=]+@[a-zA-Z0-9-]+.[a-z]+)" & revealing ["[a-zA-Z0-9._%-=]", "[a-zA-Z0-9-]", "[a-z]"]
 // Note: this is not the perfect regex pattern for an email: this is just for testing purposes!
-function emailRegex(input: Field[]) {
+function emailRegex(input: UInt8[]) {
         const num_bytes = input.length;
         let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
         let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -143,27 +142,27 @@ function emailRegex(input: Field[]) {
         }
 
         for (let i = 0; i < num_bytes; i++) {
-                const lt0 = Field(65).lessThanOrEqual(input[i]);
+                const lt0 = new UInt8(65).lessThanOrEqual(input[i]);
                 const lt1 = input[i].lessThanOrEqual(90);
                 const and0 = lt0.and(lt1);
-                const lt2 = Field(97).lessThanOrEqual(input[i]);
+                const lt2 = new UInt8(97).lessThanOrEqual(input[i]);
                 const lt3 = input[i].lessThanOrEqual(122);
                 const and1 = lt2.and(lt3);
-                const eq0 = input[i].equals(37);
-                const eq1 = input[i].equals(45);
-                const eq2 = input[i].equals(46);
-                const eq3 = input[i].equals(48);
-                const eq4 = input[i].equals(49);
-                const eq5 = input[i].equals(50);
-                const eq6 = input[i].equals(51);
-                const eq7 = input[i].equals(52);
-                const eq8 = input[i].equals(53);
-                const eq9 = input[i].equals(54);
-                const eq10 = input[i].equals(55);
-                const eq11 = input[i].equals(56);
-                const eq12 = input[i].equals(57);
-                const eq13 = input[i].equals(61);
-                const eq14 = input[i].equals(95);
+                const eq0 = input[i].value.equals(37);
+                const eq1 = input[i].value.equals(45);
+                const eq2 = input[i].value.equals(46);
+                const eq3 = input[i].value.equals(48);
+                const eq4 = input[i].value.equals(49);
+                const eq5 = input[i].value.equals(50);
+                const eq6 = input[i].value.equals(51);
+                const eq7 = input[i].value.equals(52);
+                const eq8 = input[i].value.equals(53);
+                const eq9 = input[i].value.equals(54);
+                const eq10 = input[i].value.equals(55);
+                const eq11 = input[i].value.equals(56);
+                const eq12 = input[i].value.equals(57);
+                const eq13 = input[i].value.equals(61);
+                const eq14 = input[i].value.equals(95);
                 let multi_or0 = Bool(false);
                 multi_or0 = multi_or0.or(and0);
                 multi_or0 = multi_or0.or(and1);
@@ -189,7 +188,7 @@ function emailRegex(input: Field[]) {
                 multi_or1 = multi_or1.or(and3);
                 states[i+1][1] = multi_or1;
                 state_changed[i] = state_changed[i].or(states[i+1][1]);
-                const eq15 = input[i].equals(64);
+                const eq15 = input[i].value.equals(64);
                 const and4 = states[i][1].and(eq15);
                 states[i+1][2] = and4;
                 state_changed[i] = state_changed[i].or(states[i+1][2]);
@@ -231,7 +230,6 @@ function emailRegex(input: Field[]) {
         for (let i = 0; i <= num_bytes; i++) {
                 final_state_result = final_state_result.or(states[i][5]);
         }
-
         const out = final_state_result;
 
         const msg_bytes = num_bytes - 1;
@@ -254,9 +252,9 @@ function emailRegex(input: Field[]) {
                 is_substr0[i][1] = is_substr0[i][0].or(states[i+1][0].and(states[i+2][1]));
                 is_substr0[i][2] = is_substr0[i][1].or(states[i+1][1].and(states[i+2][1]));
                 is_reveal0[i] = is_substr0[i][2].and(is_consecutive[i][1]);
-                reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+                reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
         }
-        reveal0.unshift(input[0].mul(states[1][1].toField()));
+        reveal0.unshift(input[0].value.mul(states[1][1].toField()));
         reveal.push(reveal0);
 
         // the 1-th substring transitions: [[2,3],[3,3]]
@@ -268,7 +266,7 @@ function emailRegex(input: Field[]) {
                 is_substr1[i][1] = is_substr1[i][0].or(states[i+1][2].and(states[i+2][3]));
                 is_substr1[i][2] = is_substr1[i][1].or(states[i+1][3].and(states[i+2][3]));
                 is_reveal1[i] = is_substr1[i][2].and(is_consecutive[i][1]);
-                reveal1[i] = input[i+1].mul(is_reveal1[i].toField());
+                reveal1[i] = input[i+1].value.mul(is_reveal1[i].toField());
         }
         reveal.push(reveal1);
 
@@ -281,15 +279,15 @@ function emailRegex(input: Field[]) {
                 is_substr2[i][1] = is_substr2[i][0].or(states[i+1][4].and(states[i+2][5]));
                 is_substr2[i][2] = is_substr2[i][1].or(states[i+1][5].and(states[i+2][5]));
                 is_reveal2[i] = is_substr2[i][2].and(is_consecutive[i][1]);
-                reveal2[i] = input[i+1].mul(is_reveal2[i].toField());
+                reveal2[i] = input[i+1].value.mul(is_reveal2[i].toField());
         }
         reveal.push(reveal2);
 
         return { out, reveal };
 }
 
-// ([a-zA-Z0-9]|\\+|/|=)+ & revealing all
-function base64Regex(input: Field[]) {
+// "([a-zA-Z0-9]|\\+|/|=)+" & revealing all
+function base64Regex(input: UInt8[]) {
         const num_bytes = input.length;
         let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
         let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -300,25 +298,25 @@ function base64Regex(input: Field[]) {
         }
 
         for (let i = 0; i < num_bytes; i++) {
-                const lt0 = Field(65).lessThanOrEqual(input[i]);
+                const lt0 = new UInt8(65).lessThanOrEqual(input[i]);
                 const lt1 = input[i].lessThanOrEqual(90);
                 const and0 = lt0.and(lt1);
-                const lt2 = Field(97).lessThanOrEqual(input[i]);
+                const lt2 = new UInt8(97).lessThanOrEqual(input[i]);
                 const lt3 = input[i].lessThanOrEqual(122);
                 const and1 = lt2.and(lt3);
-                const eq0 = input[i].equals(43);
-                const eq1 = input[i].equals(47);
-                const eq2 = input[i].equals(48);
-                const eq3 = input[i].equals(49);
-                const eq4 = input[i].equals(50);
-                const eq5 = input[i].equals(51);
-                const eq6 = input[i].equals(52);
-                const eq7 = input[i].equals(53);
-                const eq8 = input[i].equals(54);
-                const eq9 = input[i].equals(55);
-                const eq10 = input[i].equals(56);
-                const eq11 = input[i].equals(57);
-                const eq12 = input[i].equals(61);
+                const eq0 = input[i].value.equals(43);
+                const eq1 = input[i].value.equals(47);
+                const eq2 = input[i].value.equals(48);
+                const eq3 = input[i].value.equals(49);
+                const eq4 = input[i].value.equals(50);
+                const eq5 = input[i].value.equals(51);
+                const eq6 = input[i].value.equals(52);
+                const eq7 = input[i].value.equals(53);
+                const eq8 = input[i].value.equals(54);
+                const eq9 = input[i].value.equals(55);
+                const eq10 = input[i].value.equals(56);
+                const eq11 = input[i].value.equals(57);
+                const eq12 = input[i].value.equals(61);
                 let multi_or0 = Bool(false);
                 multi_or0 = multi_or0.or(and0);
                 multi_or0 = multi_or0.or(and1);
@@ -372,16 +370,16 @@ function base64Regex(input: Field[]) {
                 is_substr0[i][1] = is_substr0[i][0].or(states[i+1][0].and(states[i+2][1]));
                 is_substr0[i][2] = is_substr0[i][1].or(states[i+1][1].and(states[i+2][1]));
                 is_reveal0[i] = is_substr0[i][2].and(is_consecutive[i][1]);
-                reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+                reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
         }
-        reveal0.unshift(input[0].mul(states[1][1].toField()));
+        reveal0.unshift(input[0].value.mul(states[1][1].toField()));
         reveal.push(reveal0);
 
         return { out, reveal };
 }
 
-// "(mina|MINA)+" & revealing ['mina', 'MINA']
-function minaRegex(input: Field[]) {
+// "(mina|MINA)+" & revealing ["mina", "MINA"]
+function minaRegex(input: UInt8[]) {
         const num_bytes = input.length;
         let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
         let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -392,7 +390,7 @@ function minaRegex(input: Field[]) {
         }
 
         for (let i = 0; i < num_bytes; i++) {
-                const eq0 = input[i].equals(77);
+                const eq0 = input[i].value.equals(77);
                 const and0 = states[i][0].and(eq0);
                 const and1 = states[i][7].and(eq0);
                 let multi_or0 = Bool(false);
@@ -400,7 +398,7 @@ function minaRegex(input: Field[]) {
                 multi_or0 = multi_or0.or(and1);
                 states[i+1][1] = multi_or0;
                 state_changed[i] = state_changed[i].or(states[i+1][1]);
-                const eq1 = input[i].equals(109);
+                const eq1 = input[i].value.equals(109);
                 const and2 = states[i][0].and(eq1);
                 const and3 = states[i][7].and(eq1);
                 let multi_or1 = Bool(false);
@@ -408,25 +406,25 @@ function minaRegex(input: Field[]) {
                 multi_or1 = multi_or1.or(and3);
                 states[i+1][2] = multi_or1;
                 state_changed[i] = state_changed[i].or(states[i+1][2]);
-                const eq2 = input[i].equals(73);
+                const eq2 = input[i].value.equals(73);
                 const and4 = states[i][1].and(eq2);
                 states[i+1][3] = and4;
                 state_changed[i] = state_changed[i].or(states[i+1][3]);
-                const eq3 = input[i].equals(105);
+                const eq3 = input[i].value.equals(105);
                 const and5 = states[i][2].and(eq3);
                 states[i+1][4] = and5;
                 state_changed[i] = state_changed[i].or(states[i+1][4]);
-                const eq4 = input[i].equals(78);
+                const eq4 = input[i].value.equals(78);
                 const and6 = states[i][3].and(eq4);
                 states[i+1][5] = and6;
                 state_changed[i] = state_changed[i].or(states[i+1][5]);
-                const eq5 = input[i].equals(110);
+                const eq5 = input[i].value.equals(110);
                 const and7 = states[i][4].and(eq5);
                 states[i+1][6] = and7;
                 state_changed[i] = state_changed[i].or(states[i+1][6]);
-                const eq6 = input[i].equals(65);
+                const eq6 = input[i].value.equals(65);
                 const and8 = states[i][5].and(eq6);
-                const eq7 = input[i].equals(97);
+                const eq7 = input[i].value.equals(97);
                 const and9 = states[i][6].and(eq7);
                 let multi_or2 = Bool(false);
                 multi_or2 = multi_or2.or(and8);
@@ -466,9 +464,9 @@ function minaRegex(input: Field[]) {
                 is_substr0[i][4] = is_substr0[i][3].or(states[i+1][4].and(states[i+2][6]));
                 is_substr0[i][5] = is_substr0[i][4].or(states[i+1][6].and(states[i+2][7]));
                 is_reveal0[i] = is_substr0[i][5].and(is_consecutive[i][1]);
-                reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+                reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
         }
-        reveal0.unshift(input[0].mul(states[1][2].toField()));
+        reveal0.unshift(input[0].value.mul(states[1][2].toField()));
         reveal.push(reveal0);
 
         // the 1-th substring transitions: [[0,1],[7,1],[1,3],[3,5],[5,7]]
@@ -483,16 +481,16 @@ function minaRegex(input: Field[]) {
                 is_substr1[i][4] = is_substr1[i][3].or(states[i+1][3].and(states[i+2][5]));
                 is_substr1[i][5] = is_substr1[i][4].or(states[i+1][5].and(states[i+2][7]));
                 is_reveal1[i] = is_substr1[i][5].and(is_consecutive[i][1]);
-                reveal1[i] = input[i+1].mul(is_reveal1[i].toField());
+                reveal1[i] = input[i+1].value.mul(is_reveal1[i].toField());
         }
-        reveal1.unshift(input[0].mul(states[1][1].toField()));
+        reveal1.unshift(input[0].value.mul(states[1][1].toField()));
         reveal.push(reveal1);
 
         return { out, reveal };
 }
 
-// "a:[^abcdefghijklmnopqrstuvwxyz]+." & revealing ['[^abcdefghijklmnopqrstuvwxyz]']
-function negateRegex(input: Field[]) {
+// "a:[^abcdefghijklmnopqrstuvwxyz]+." & revealing ["[^abcdefghijklmnopqrstuvwxyz]"]
+function negateRegex(input: UInt8[]) {
         const num_bytes = input.length;
         let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
         let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -503,10 +501,10 @@ function negateRegex(input: Field[]) {
         }
 
         for (let i = 0; i < num_bytes; i++) {
-                const lt0 = Field(97).lessThanOrEqual(input[i]);
+                const lt0 = new UInt8(97).lessThanOrEqual(input[i]);
                 const lt1 = input[i].lessThanOrEqual(122);
                 const and0 = lt0.and(lt1);
-                const eq0 = input[i].equals(46);
+                const eq0 = input[i].value.equals(46);
                 let multi_or0 = Bool(false);
                 multi_or0 = multi_or0.or(and0);
                 multi_or0 = multi_or0.or(eq0);
@@ -520,11 +518,11 @@ function negateRegex(input: Field[]) {
                 const and3 = states[i][1].and(eq0);
                 states[i+1][2] = and3;
                 state_changed[i] = state_changed[i].or(states[i+1][2]);
-                const eq1 = input[i].equals(97);
+                const eq1 = input[i].value.equals(97);
                 const and4 = states[i][0].and(eq1);
                 states[i+1][3] = and4;
                 state_changed[i] = state_changed[i].or(states[i+1][3]);
-                const eq2 = input[i].equals(58);
+                const eq2 = input[i].value.equals(58);
                 const and5 = states[i][3].and(eq2);
                 states[i+1][4] = and5;
                 state_changed[i] = state_changed[i].or(states[i+1][4]);
@@ -535,7 +533,6 @@ function negateRegex(input: Field[]) {
         for (let i = 0; i <= num_bytes; i++) {
                 final_state_result = final_state_result.or(states[i][2]);
         }
-
         const out = final_state_result;
 
         const msg_bytes = num_bytes - 1;
@@ -558,7 +555,7 @@ function negateRegex(input: Field[]) {
                 is_substr0[i][1] = is_substr0[i][0].or(states[i+1][1].and(states[i+2][1]));
                 is_substr0[i][2] = is_substr0[i][1].or(states[i+1][4].and(states[i+2][1]));
                 is_reveal0[i] = is_substr0[i][2].and(is_consecutive[i][1]);
-                reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+                reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
         }
         reveal.push(reveal0);
 
@@ -566,7 +563,7 @@ function negateRegex(input: Field[]) {
 }
 
 // "[^aeiou]+" & revealing all
-export function negateVowel(input: Field[]) {
+export function negateVowel(input: UInt8[]) {
         const num_bytes = input.length;
         let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
         let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -577,11 +574,11 @@ export function negateVowel(input: Field[]) {
         }
 
         for (let i = 0; i < num_bytes; i++) {
-                const eq0 = input[i].equals(97);
-                const eq1 = input[i].equals(101);
-                const eq2 = input[i].equals(105);
-                const eq3 = input[i].equals(111);
-                const eq4 = input[i].equals(117);
+                const eq0 = input[i].value.equals(97);
+                const eq1 = input[i].value.equals(101);
+                const eq2 = input[i].value.equals(105);
+                const eq3 = input[i].value.equals(111);
+                const eq4 = input[i].value.equals(117);
                 let multi_or0 = Bool(false);
                 multi_or0 = multi_or0.or(eq0);
                 multi_or0 = multi_or0.or(eq1);
@@ -602,7 +599,6 @@ export function negateVowel(input: Field[]) {
         for (let i = 1; i <= num_bytes; i++) {
                 final_state_result = final_state_result.and(states[i][1]);
         }
-
         const out = final_state_result;
 
         const msg_bytes = num_bytes - 1;
@@ -625,9 +621,9 @@ export function negateVowel(input: Field[]) {
                 is_substr0[i][1] = is_substr0[i][0].or(states[i+1][0].and(states[i+2][1]));
                 is_substr0[i][2] = is_substr0[i][1].or(states[i+1][1].and(states[i+2][1]));
                 is_reveal0[i] = is_substr0[i][2].and(is_consecutive[i][1]);
-                reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+                reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
         }
-        reveal0.unshift(input[0].mul(states[1][1].toField()));
+        reveal0.unshift(input[0].value.mul(states[1][1].toField()));
         reveal.push(reveal0);
 
         return { out, reveal };
diff --git a/src/zkRegex.test.ts b/src/zkRegex.test.ts
index ce2dd3b..8de150d 100644
--- a/src/zkRegex.test.ts
+++ b/src/zkRegex.test.ts
@@ -1,4 +1,4 @@
-import { Bool, Field, Bytes } from 'o1js';
+import { Bool, Field, Bytes, UInt8 } from 'o1js';
 import {
   simpleRegex, 
   emailRegex, 
@@ -47,7 +47,7 @@ function utf8BytesToString(bytes: bigint[]): string {
 
 type OutputType = Field | Bool;
 
-type ZkRegexFunction<T extends OutputType> = (input: Field[]) => {
+type ZkRegexFunction<T extends OutputType> = (input: UInt8[]) => {
   out: T;
   reveal: Field[][];
 }
@@ -68,7 +68,7 @@ function testZkRegex<T extends OutputType>(
   isValidExpected: T,
   expectedSubstring?: string[]
 ) {
-  const inputBytes = Bytes.fromString(input).toFields();
+  const inputBytes = Bytes.fromString(input).bytes;
 
   const { out, reveal } = zkRegexFunction(inputBytes);
 
diff --git a/src/zkRegex.ts b/src/zkRegex.ts
index 0775771..40b9bbc 100644
--- a/src/zkRegex.ts
+++ b/src/zkRegex.ts
@@ -6,7 +6,7 @@ import {
 } from "./regexToDfa.js";
 
 // Handle different commands based on 'countEnabled' and 'substringEnabled' boolean arguments
-const rawRegex = process.argv[2] ?? "name: [A-Z][a-z]+";
+const rawRegex = process.argv[2];
 let countEnabled = false;
 let substringEnabled = false;
 if (process.argv[3]) {
@@ -164,7 +164,7 @@ for (let i = 1; i < N; i++) {
             const min = min_max[0];
             const max = min_max[1];
             if (range_checks[min][max] === undefined) {
-                lines.push(`\tconst lt${lt_i} = Field(${min}).lessThanOrEqual(input[i]);`);
+                lines.push(`\tconst lt${lt_i} = new UInt8(${min}).lessThanOrEqual(input[i]);`);
 
                 lines.push(`\tconst lt${lt_i + 1} = input[i].lessThanOrEqual(${max});`);
 
@@ -183,7 +183,7 @@ for (let i = 1; i < N; i++) {
 
         for (let code of vals) {
             if (eq_checks[code] === undefined) {
-                lines.push(`\tconst eq${eq_i} = input[i].equals(${code});`);
+                lines.push(`\tconst eq${eq_i} = input[i].value.equals(${code});`);
                 
                 eq_outputs.push(['eq', eq_i]);
                 eq_checks[code] = eq_i;
@@ -338,9 +338,9 @@ function substring_lines(substrDefsArray: [number, number][][]): string {
         }
 
         reveal += `\t\tis_reveal${idx}[i] = is_substr${idx}[i][${numDefs}].and(is_consecutive[i][1]);\n`;
-        reveal += `\t\treveal${idx}[i] = input[i+1].mul(is_reveal${idx}[i].toField());\n`;
+        reveal += `\t\treveal${idx}[i] = input[i+1].value.mul(is_reveal${idx}[i].toField());\n`;
         reveal += "\t}\n";
-        reveal += includes_start ? `\treveal${idx}.unshift(input[0].mul(states[1][${startIndex}].toField()));\n` : '';
+        reveal += includes_start ? `\treveal${idx}.unshift(input[0].value.mul(states[1][${startIndex}].toField()));\n` : '';
         reveal += `\treveal.push(reveal${idx});`;
     }
     
@@ -366,7 +366,7 @@ if (substringEnabled) {
 }
 
 export const functionString = 
-    "\n(input: Field[]) {\n" +
+    "\n(input: UInt8[]) {\n" +
     lines.join('\n\t') + 
     reveal_lines + 
     "\n}";
@@ -414,6 +414,6 @@ function extractSubstrTransitions(
 //TODO Declare state_changed outside of the loop declaration
 //TODO Refactor is_substr calculation
 //TODO Fix occurence compiler code when regex ends with repetition operator +
-//TODO organize zkRegex into a class
+//TODO Organize zkRegex compiler into a class
 //TODO Add the option to reveal substrings based on search functions .i.e. isDigit, isNumber etc...
 //TODO Refine notations for both compile and compiled code
\ No newline at end of file
diff --git a/src/zkapp.ts b/src/zkapp.ts
index bad0eee..e772994 100644
--- a/src/zkapp.ts
+++ b/src/zkapp.ts
@@ -12,6 +12,7 @@ import {
     Mina,
     PrivateKey,
     AccountUpdate,
+    UInt8,
 } from 'o1js';
 
 class Bytes16 extends Bytes(16) {}
@@ -29,7 +30,7 @@ export class RegexZkApp extends SmartContract {
 
     @method async guessName(statement: Bytes16) {
         // This regex pattern specifies an alphabetic name of length 4 where the first letter is capitalized
-        let { out, reveal } = nameRegex(statement.toFields());
+        let { out, reveal } = nameRegex(statement.bytes);
         out.assertEquals(1, "Please enter only one valid name!");
 
         const name = reveal[0];
@@ -86,9 +87,9 @@ console.log(
 console.log('Admin name is discovered: ', zkAppInstance.isDiscovered.get().toBoolean());
 
 
-// "name: [A-Z][a-z][a-z][a-z]" & revealing all
+// "[A-Z][a-z][a-z][a-z]" & revealing all
 // Basically, the regex pattern is to give an alphabetic name of length 4 where the first letter is capital
-function nameRegex(input: Field[]) {
+function nameRegex(input: UInt8[]) {
     const num_bytes = input.length;
     let states: Bool[][] = Array.from({ length: num_bytes + 1 }, () => []);
     let state_changed: Bool[] = Array.from({ length: num_bytes }, () => Bool(false));
@@ -99,13 +100,13 @@ function nameRegex(input: Field[]) {
     }
 
     for (let i = 0; i < num_bytes; i++) {
-        const lt0 = Field(65).lessThanOrEqual(input[i]);
+        const lt0 = new UInt8(65).lessThanOrEqual(input[i]);
         const lt1 = input[i].lessThanOrEqual(90);
         const and0 = lt0.and(lt1);
         const and1 = states[i][0].and(and0);
         states[i+1][1] = and1;
         state_changed[i] = state_changed[i].or(states[i+1][1]);
-        const lt2 = Field(97).lessThanOrEqual(input[i]);
+        const lt2 = new UInt8(97).lessThanOrEqual(input[i]);
         const lt3 = input[i].lessThanOrEqual(122);
         const and2 = lt2.and(lt3);
         const and3 = states[i][1].and(and2);
@@ -149,9 +150,9 @@ function nameRegex(input: Field[]) {
         is_substr0[i][3] = is_substr0[i][2].or(states[i+1][2].and(states[i+2][3]));
         is_substr0[i][4] = is_substr0[i][3].or(states[i+1][3].and(states[i+2][4]));
         is_reveal0[i] = is_substr0[i][4].and(is_consecutive[i][1]);
-        reveal0[i] = input[i+1].mul(is_reveal0[i].toField());
+        reveal0[i] = input[i+1].value.mul(is_reveal0[i].toField());
     }
-    reveal0.unshift(input[0].mul(states[1][1].toField()));
+    reveal0.unshift(input[0].value.mul(states[1][1].toField()));
     reveal.push(reveal0);
 
     return { out, reveal };