正規表現テスター
正規表現をオンラインでテストします。パターンをマッチさせ、正規表現をテストし、リアルタイムで結果を確認します。
正規表現パターン
テストテキスト
機能紹介
The Regex Tester tool helps you design, test, and debug regular expressions in real time. See all matches, groups, and errors instantly as you type, so you can build reliable patterns faster.
このツールを使うタイミング
Use this tool whenever you need to test a regular expression: cleaning text data, validating user input, extracting information from logs, or learning how complex patterns behave.
使い方
Enter your regular expression
Type or paste a regex pattern into the pattern input box. You can include anchors, groups, lookarounds, and flags.
Provide sample test text
Paste example text into the test area, such as a log snippet, CSV line, or form input you want to validate.
Adjust flags and options
Toggle flags like global, multiline, or case-insensitive to see how they change the matches in real time.
Inspect matches and groups
Review highlighted matches in the text and detailed lists of capturing groups to verify your pattern behaves as expected.
使用例
Validating email addresses
Before adding a regex-based email validator to your backend, test the pattern here with a variety of real-world email examples to avoid blocking valid users.
Extracting IDs from log files
Paste a few lines of log output and design a regex that captures request IDs or user IDs into groups, then copy the final pattern into your scripts.