diff --git a/src/main/java/org/philzen/oss/testng/MigrateMismatchedAssertions.java b/src/main/java/org/philzen/oss/testng/MigrateMismatchedAssertions.java
new file mode 100644
index 00000000..153cb4fc
--- /dev/null
+++ b/src/main/java/org/philzen/oss/testng/MigrateMismatchedAssertions.java
@@ -0,0 +1,100 @@
+package org.philzen.oss.testng;
+
+import org.openrewrite.*;
+import org.openrewrite.internal.lang.NonNullApi;
+import org.openrewrite.java.JavaParser;
+import org.openrewrite.java.JavaTemplate;
+import org.openrewrite.java.JavaVisitor;
+import org.openrewrite.java.search.UsesMethod;
+import org.openrewrite.java.search.UsesType;
+import org.openrewrite.java.template.internal.AbstractRefasterJavaVisitor;
+import org.openrewrite.java.tree.J;
+import org.philzen.oss.utils.JupiterJavaParser;
+
+import java.util.function.Function;
+
+import static org.openrewrite.java.template.internal.AbstractRefasterJavaVisitor.EmbeddingOption.SHORTEN_NAMES;
+import static org.openrewrite.java.template.internal.AbstractRefasterJavaVisitor.EmbeddingOption.SIMPLIFY_BOOLEANS;
+
+@NonNullApi
+public class MigrateMismatchedAssertions extends Recipe {
+
+    @Override
+    public String getDisplayName() {
+        return "Replace `Assert#assertEquals(actual[], expected[], delta [, message])` for float and double inputs";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Replace `org.testng.Assert#assertEquals(actual[], expected[], delta [, message])` with custom `org.junit.jupiter.api.Assertions#assertAll(() -> {})`.";
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        JavaVisitor<ExecutionContext> javaVisitor = new AbstractRefasterJavaVisitor() {
+
+            final Function<String, JavaTemplate> before = (type) -> JavaTemplate
+                    .builder("org.testng.Assert.assertEquals(#{actual:anyArray(%s)}, #{expected:anyArray(%s)}, #{delta:any(%s)});".replace("%s", type))
+                    .javaParser(JavaParser.fromJavaVersion().classpath(JavaParser.runtimeClasspath()))
+                    .build();
+
+            final Function<String, JavaTemplate> beforeWithMsg = (type) -> JavaTemplate
+                    .builder("org.testng.Assert.assertEquals(#{actual:anyArray(%s)}, #{expected:anyArray(%s)}, #{delta:any(%s)}, #{message:any(java.lang.String)});".replace("%s", type))
+                    .javaParser(JavaParser.fromJavaVersion().classpath(JavaParser.runtimeClasspath()))
+                    .build();
+
+            final JavaTemplate after = JavaTemplate
+                    .builder("Assertions.assertAll(()->{\n    Assertions.assertEquals(#{expected:anyArray(float)}.length, #{actual:anyArray(float)}.length, \"Arrays don't have the same size.\");\n    for (int i = 0; i < #{actual}.length; i++) {\n        Assertions.assertEquals(#{expected}[i], #{actual}[i], #{delta:any(float)});\n    }\n});")
+                    .imports("org.junit.jupiter.api.Assertions")
+                    .javaParser(JupiterJavaParser.get()).build();
+
+            final JavaTemplate afterWithMsg = JavaTemplate
+                    .builder("Assertions.assertAll(()->{\n    Assertions.assertEquals(#{expected:anyArray(float)}.length, #{actual:anyArray(float)}.length, \"Arrays don't have the same size.\");\n    for (int i = 0; i < #{actual}.length; i++) {\n        Assertions.assertEquals(#{expected}[i], #{actual}[i], #{delta:any(float)}, #{message:any(String)});\n    }\n});")
+                    .imports("org.junit.jupiter.api.Assertions")
+                    .javaParser(JupiterJavaParser.get()).build();
+
+            @Override
+            public J visitMethodInvocation(J.MethodInvocation elem, ExecutionContext ctx) {
+                JavaTemplate.Matcher matcher;
+                if ((matcher = before.apply("float").matcher(getCursor())).find()
+                || (matcher = before.apply("double").matcher(getCursor())).find())
+                {
+                    return embed(ctx, after.apply(
+                            getCursor(),
+                            elem.getCoordinates().replace(),
+                            matcher.parameter(1),
+                            matcher.parameter(0),
+                            matcher.parameter(2))
+                    );
+                }
+                if ((matcher = beforeWithMsg.apply("float").matcher(getCursor())).find()
+                        || (matcher = beforeWithMsg.apply("double").matcher(getCursor())).find())
+                {
+                    return embed(ctx, afterWithMsg.apply(
+                            getCursor(),
+                            elem.getCoordinates().replace(),
+                            matcher.parameter(1),
+                            matcher.parameter(0),
+                            matcher.parameter(2),
+                            matcher.parameter(3)
+                    ));
+                }
+                return super.visitMethodInvocation(elem, ctx);
+            }
+
+            private J embed(ExecutionContext ctx, J j) {
+                maybeRemoveImport("org.testng.Assert");
+                maybeAddImport("org.junit.jupiter.api.Assertions");
+                return super.embed(j, getCursor(), ctx, SHORTEN_NAMES, SIMPLIFY_BOOLEANS);
+            }
+        };
+
+        return Preconditions.check(
+                Preconditions.and(
+                        new UsesType<>("org.testng.Assert", true),
+                        new UsesMethod<>("org.testng.Assert assertEquals(..)")
+                ),
+                javaVisitor
+        );
+    }
+}
diff --git a/src/test/java/org/philzen/oss/research/ApiComparisonTest.java b/src/test/java/org/philzen/oss/research/ApiComparisonTest.java
index 59c0c67f..1c619764 100644
--- a/src/test/java/org/philzen/oss/research/ApiComparisonTest.java
+++ b/src/test/java/org/philzen/oss/research/ApiComparisonTest.java
@@ -55,6 +55,31 @@ public class ApiComparisonTest {
             thisWillFail(() -> Assertions.assertEquals(2d, actual, .999d));
         }
 
+        @Tag("missing")
+        @Test void doubleArrayDelta() {
+            final double[] expected = new double[] {0d, 10d};
+            final double[] actual = new double[] {1d, 9d};
+            thisWillPass(() -> Assert.assertEquals(actual, expected, 1d));
+            // there is no equivalent in Jupiter :/
+
+            thisWillFail(() -> Assert.assertEquals(actual, expected, .999d));
+            // there is no equivalent in Jupiter :/
+
+            // possible migration equivalent
+            thisWillPass(() -> Assertions.assertAll(() -> {
+                Assertions.assertEquals(expected.length, actual.length, "Arrays don't have the same size.");
+                for (int i = 0; i < actual.length; i++) {
+                    Assertions.assertEquals(expected[i], actual[i], 1d);
+                }
+            }));
+            thisWillFail(() -> Assertions.assertAll(() -> {
+                Assertions.assertEquals(expected.length, actual.length, "Arrays don't have the same size.");
+                for (int i = 0; i < actual.length; i++) {
+                    Assertions.assertEquals(expected[i], actual[i], .999d);
+                }
+            }));
+        }
+
         @Test void floatDelta() {
             final float actual = 1f;
 
@@ -64,6 +89,31 @@ public class ApiComparisonTest {
             thisWillFail(() -> Assert.assertEquals(actual, 2f, .999f));
             thisWillFail(() -> Assertions.assertEquals(2f, actual, .999f));
         }
+
+        @Tag("missing")
+        @Test void floatArrayDelta() {
+            final double[] expected = new double[] {0d, 10f};
+            final double[] actual = new double[] {1f, 9f};
+            thisWillPass(() -> Assert.assertEquals(actual, expected, 1f));
+            // there is no equivalent in Jupiter :/
+
+            thisWillFail(() -> Assert.assertEquals(actual, expected, .999f));
+            // there is no equivalent in Jupiter :/
+
+            // possible migration equivalent
+            thisWillPass(() -> Assertions.assertAll(() -> {
+                Assertions.assertEquals(expected.length, actual.length, "Arrays don't have the same size.");
+                for (int i = 0; i < actual.length; i++) {
+                    Assertions.assertEquals(expected[i], actual[i], 1f);
+                }
+            }));
+            thisWillFail(() -> Assertions.assertAll(() -> {
+                Assertions.assertEquals(expected.length, actual.length, "Arrays don't have the same size.");
+                for (int i = 0; i < actual.length; i++) {
+                    Assertions.assertEquals(expected[i], actual[i], .999f);
+                }
+            }));
+        }
     }
 
     @Nested class assertNotEquals {
diff --git a/src/test/java/org/philzen/oss/testng/MigrateMismatchedAssertionsTest.java b/src/test/java/org/philzen/oss/testng/MigrateMismatchedAssertionsTest.java
new file mode 100644
index 00000000..f353453c
--- /dev/null
+++ b/src/test/java/org/philzen/oss/testng/MigrateMismatchedAssertionsTest.java
@@ -0,0 +1,89 @@
+package org.philzen.oss.testng;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.java.Assertions.java;
+
+class MigrateMismatchedAssertionsTest implements RewriteTest {
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new MigrateMismatchedAssertions());
+    }
+
+    @ValueSource(strings = {"float[]", "double[]"})
+    @ParameterizedTest
+    void deltaFunctionForArraysIsMigrated(String type) {
+        //language=java
+        rewriteRun(java(
+          """
+          import org.testng.Assert;
+          
+          class MyTest {
+              void testMethod() {
+                  %s actual;
+                  %s expected;
+          
+                  Assert.assertEquals(actual, expected, %s);
+              }
+          }
+          """.formatted(type, type, type.equals("float[]") ? "0.1f" : "0.2d"),
+          """
+          import org.junit.jupiter.api.Assertions;
+          
+          class MyTest {
+              void testMethod() {
+                  %s actual;
+                  %s expected;
+          
+                  Assertions.assertAll(() -> {
+                      Assertions.assertEquals(expected.length, actual.length, "Arrays don't have the same size.");
+                      for (int i = 0; i < actual.length; i++) {
+                          Assertions.assertEquals(expected[i], actual[i], %s);
+                      }
+                  });
+              }
+          }
+          """.formatted(type, type, type.equals("float[]") ? "0.1f" : "0.2d")
+        ));
+    }
+
+    @ValueSource(strings = {"float[]", "double[]"})
+    @ParameterizedTest
+    void deltaFunctionForArraysIsMigratedWithMessage(String type) {
+        //language=java
+        rewriteRun(java(
+          """
+          import org.testng.Assert;
+          
+          class MyTest {
+              void testMethod() {
+                  %s actual;
+                  %s expected;
+          
+                  Assert.assertEquals(actual, expected, %s, "Those values are way off.");
+              }
+          }
+          """.formatted(type, type, type.equals("float[]") ? "0.1f" : "0.2d"),
+          """
+          import org.junit.jupiter.api.Assertions;
+          
+          class MyTest {
+              void testMethod() {
+                  %s actual;
+                  %s expected;
+          
+                  Assertions.assertAll(() -> {
+                      Assertions.assertEquals(expected.length, actual.length, "Arrays don't have the same size.");
+                      for (int i = 0; i < actual.length; i++) {
+                          Assertions.assertEquals(expected[i], actual[i], %s, "Those values are way off.");
+                      }
+                  });
+              }
+          }
+          """.formatted(type, type, type.equals("float[]") ? "0.1f" : "0.2d")
+        ));
+    }
+}
\ No newline at end of file