diff --git a/packages/app/package.json b/packages/app/package.json
index ddc8f13..03aafb8 100644
--- a/packages/app/package.json
+++ b/packages/app/package.json
@@ -27,6 +27,7 @@
     "@zk-email/circuits": "6.1.1",
     "@zk-email/helpers": "6.1.1",
     "@zk-email/zk-email-sdk": "^1.0.5",
+    "@zk-email/relayer-utils": "^0.4.2",
     "archiver": "^7.0.1",
     "class-variance-authority": "^0.7.0",
     "clsx": "^2.1.1",
diff --git a/packages/app/src/app/submit/email/action.ts b/packages/app/src/app/submit/email/action.ts
index 7253659..4d7cdf4 100644
--- a/packages/app/src/app/submit/email/action.ts
+++ b/packages/app/src/app/submit/email/action.ts
@@ -3,6 +3,7 @@ import { z } from 'zod';
 import { formSchema } from '../form';
 import { generateCodeLibrary } from '@/lib/code-gen/gen';
 import { verifyDKIMSignature } from "@zk-email/helpers/dist/dkim";
+import { extractMatches, extractMatchesWasm, Values } from '@/lib/regex';
 
 export interface ProcessEmailResult {
     error: boolean,
@@ -73,7 +74,7 @@ export async function processEmail(values: z.infer<typeof formSchema>, email: st
     }
 
     // Apply regex
-    const matches = extractMatches(headerString, bodyString, values.parameters.values as Values[]);
+    const matches = await extractMatchesWasm(headerString, bodyString, values.parameters.values as Values[]);
 
     const parameters = {
         ...values.parameters,
@@ -94,62 +95,4 @@ export async function processEmail(values: z.infer<typeof formSchema>, email: st
         parameters: res,
         matches,
     }
-}
-
-interface Values {
-    name: string,
-    location: "header" | "body",
-    parts: {
-        regex_def: string,
-        is_public: boolean,
-    }[],
-}
-
-function extractMatches(headerString: string, bodyString: string | undefined, values: Values[]) {
-    const regexes = values.map((v: any) => {
-        let publicGroups: number[] = [];
-        let index = 1;
-        const regex = v.parts.reduce((acc: any, part: any) => {
-            if (part.regex_def.match(/\([^\)]+/)) index++;
-            if (part.is_public) {
-                publicGroups.push(index);
-                index++;
-                return acc + "(" + part.regex_def + ")"
-            } 
-            return acc + part.regex_def
-        }, "");
-        return {
-            regex,
-            publicGroups,
-            name: v.name,
-            location: v.location,
-        }
-    })
-
-    let matches = []
-
-    for (const regex of regexes) {
-        if (regex.location == "body" && bodyString) {
-            const match = bodyString.match(regex.regex)
-            if (match) {
-                for (const group of regex.publicGroups) {
-                    matches.push({
-                        name: regex.name,
-                        match: match[group],
-                    })
-                }
-            }
-        } else {
-            const match = headerString.match(regex.regex)
-            if (match) {
-                for (const group of regex.publicGroups) {
-                    matches.push({
-                        name: regex.name,
-                        match: match[group],
-                    })
-                }
-            }
-        }
-    }
-    return matches;
 }
\ No newline at end of file
diff --git a/packages/app/src/lib/regex.ts b/packages/app/src/lib/regex.ts
new file mode 100644
index 0000000..20fa78c
--- /dev/null
+++ b/packages/app/src/lib/regex.ts
@@ -0,0 +1,103 @@
+import initWasm, { extractSubstr, extractSubstrIdxes } from "@zk-email/relayer-utils";
+import fs from "fs";
+
+let wasmLoaded: Promise<boolean>;
+const code = fs.readFileSync("node_modules/@zk-email/relayer-utils/relayer_utils_bg.wasm");
+wasmLoaded = initWasm({ module_or_path: code }).then(() => {
+    return true;
+})
+
+export interface Values {
+    name: string,
+    location: "header" | "body",
+    parts: {
+        regex_def: string,
+        is_public: boolean,
+    }[],
+}
+
+export function extractMatches(headerString: string, bodyString: string | undefined, values: Values[]) {
+    const regexes = values.map((v: any) => {
+        let publicGroups: number[] = [];
+        let index = 1;
+        const regex = v.parts.reduce((acc: any, part: any) => {
+            const regexWithoutGroup = part.regex_def.replace("(", "(?:")
+            if (part.is_public) {
+                publicGroups.push(index);
+                index++;
+                return acc + "(" + regexWithoutGroup + ")"
+            }
+            return acc + regexWithoutGroup
+        }, "");
+        return {
+            regex,
+            publicGroups,
+            name: v.name,
+            location: v.location,
+        }
+    })
+
+    let matches = []
+
+    for (const regex of regexes) {
+        if (regex.location == "body" && bodyString) {
+            const match = bodyString.match(regex.regex)
+            if (match) {
+                for (const group of regex.publicGroups) {
+                    matches.push({
+                        name: regex.name,
+                        match: match[group],
+                    })
+                }
+            }
+        } else {
+            const match = headerString.match(regex.regex)
+            if (match) {
+                for (const group of regex.publicGroups) {
+                    matches.push({
+                        name: regex.name,
+                        match: match[group],
+                    })
+                }
+            }
+        }
+    }
+    return matches;
+}
+
+export async function extractMatchesWasm(headerString: string, bodyString: string | undefined, values: Values[]) {
+    let ready = await wasmLoaded;
+    let matches: {name: string, match: string}[] = [];
+    for (const value of values) {
+        if (value.location == "body" && bodyString) {
+            try {
+                let match = extractSubstr(bodyString, value, false)
+                if (match.length > 0) {
+                    matches = matches.concat(match.map( (m:string) => {
+                        return {
+                            name: value.name,
+                            match: m,
+                        }
+                    }));
+                }
+            } catch (e) {
+                console.error(e);
+            }
+        } else {
+            try {
+                let match = extractSubstr(headerString, value, false)
+                if (match.length > 0) {
+                    matches = matches.concat(match.map( (m:string) => {
+                        return {
+                            name: value.name,
+                            match: m,
+                        }
+                    }));
+                }
+            } catch (e) {
+                console.error(e);
+            }
+        }
+    }
+    return matches;
+}
diff --git a/packages/app/src/scripts/regex.ts b/packages/app/src/scripts/regex.ts
new file mode 100644
index 0000000..fc9e1fb
--- /dev/null
+++ b/packages/app/src/scripts/regex.ts
@@ -0,0 +1,53 @@
+// import initWasm, { extractSubstr, extractSubstrIdxes } from "@zk-email/relayer-utils";
+// import fs from "fs";
+
+import { extractMatches, extractMatchesWasm } from "@/lib/regex"
+
+// (async () => {
+//     const code = fs.readFileSync("node_modules/@zk-email/relayer-utils/relayer_utils_bg.wasm");
+//     await initWasm({module_or_path: code});
+//     const email = "subject:Congratulations mr x\r\n";
+//     const matches = extractSubstr(email, {
+//         parts: [
+//             {
+//                 "is_public": false,
+//                 "regex_def": "(\r\n|^)subject:"
+//             },
+//             {
+//                 "is_public": true,
+//                 "regex_def": "Congratulations"
+//             },
+//             {
+//                 "is_public": false,
+//                 "regex_def": "[^\r]+\r\n"
+//             }
+//         ]
+//     }, false)
+//     console.log(matches)
+// })()
+
+const matches = extractMatchesWasm("\r\nsubject:Congratulations mr x\r\n", "body", [{
+    name: "subject",
+    location: "header",
+    parts: [
+                    {
+                        "is_public": false,
+                        "regex_def": "(\r\n|^)subject:"
+                    },
+                    {
+                        "is_public": true,
+                        "regex_def": "Congratulations"
+                    },
+                    {
+                        "is_public": false,
+                        "regex_def": "[^\r]+\r\n"
+                    }
+                ],
+}, {name: "body", location: "body", parts: [
+    {
+        "is_public": true,
+        "regex_def": "body"
+    }
+]}]).then((matches) => {
+    console.log(matches)
+})
\ No newline at end of file
diff --git a/packages/app/yarn.lock b/packages/app/yarn.lock
index d4cecb6..e59df71 100644
--- a/packages/app/yarn.lock
+++ b/packages/app/yarn.lock
@@ -2531,6 +2531,11 @@
     psl "^1.9.0"
     snarkjs "https://github.com/sampritipanda/snarkjs.git#fef81fc51d17a734637555c6edbd585ecda02d9e"
 
+"@zk-email/relayer-utils@^0.4.2":
+  version "0.4.2"
+  resolved "https://registry.yarnpkg.com/@zk-email/relayer-utils/-/relayer-utils-0.4.2.tgz#8e13277c1c14ac7c17a0df60803eb8ab5a3d0091"
+  integrity sha512-IqJOQ75xou1H6LpTEekYMkSFtBKW2KNtCkbGVKg/vps3w3xso/qSzT8myHYKw7nm69bPRRMPVkhtFyyd33DDhQ==
+
 "@zk-email/zk-email-sdk@^1.0.5":
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/@zk-email/zk-email-sdk/-/zk-email-sdk-1.0.5.tgz#2ae9724653c652b87d0d9b62fcf12dc0a15ac545"