Regex Tester

Programmatic Access

Regex Tester is also callable as a free HTTP JSON API at https://aidevhub.io/api/regex-tester/ — GET with query parameters or POST with a JSON body, no authentication, CORS enabled, 50 requests/day per IP. Responses return { ok, tool, result, meta }.

curl -s "https://aidevhub.io/api/regex-tester/?pattern=%5Cd%2B&text=abc%20123%20def%20456&flags=g"

Machine-readable contract: /api/tool/regex-tester.json · All API endpoints: /agents/ · LLM site index: /llms.txt

Agent Invocation

REST API

curl "https://aidevhub.io/api/regex-tester/?pattern=%5Cd%2B&text=abc+123+def+456&flags=g"

const res = await fetch("https://aidevhub.io/api/regex-tester//api/regex-tester/", {
  method: "GET",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "pattern": "\\d+",
  "text": "abc 123 def 456",
  "flags": "g"
}),
});
const data = await res.json();
console.log(data);

import requests

res = requests.post(
    "https://aidevhub.io/api/regex-tester//api/regex-tester/",
    json={"pattern":"\\d+","text":"abc 123 def 456","flags":"g"},
)
print(res.json())

{
  "valid": true,
  "pattern": "\\d+",
  "matches": [
    {
      "match": "123",
      "index": 4
    }
  ],
  "match_count": 2
}

How to Use Regex Tester

1. 1

   Enter your regex pattern

   Type a regular expression in the pattern field (e.g., `^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$` for email). Use flags (g, i, m) as needed.

2. 2

   Input test strings to match against

   Paste or type multiple test strings in the input field. The tool will highlight all matches in real-time as you type.

3. 3

   View matches and capture groups

   See all matches highlighted with their exact positions. If your pattern has capture groups (parentheses), see the captured values listed separately.

4. 4

   Check regex explanation

   Read the auto-generated English explanation of what your regex does. This helps you debug patterns or learn regex syntax.

5. 5

   Test edge cases and iterate

   Add more test strings to cover edge cases (empty strings, special chars, long text). Refine your pattern until all cases pass.

Frequently Asked Questions