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Testeur de regex

Texte & Code · Outil en ligne gratuit

Tester les regex avec surlignage des correspondances en direct.

Équipe CoderNewbieDernière mise à jour : 2026-09-20

//g

Flags:

2 matches found

Test Text76 caractères

Highlighted Matches2 matches

Match Details

#1pos: 14"[email protected]"groups: [hello, example.com]

#2pos: 35"[email protected]"groups: [support, ez4code.dev]

Surlignage en direct

Voyez les correspondances surlignées en temps réel pendant que vous tapez votre motif et votre texte de test.

Groupes de capture

Inspectez chaque groupe de capture pour chaque correspondance, avec position et valeur clairement affichées.

Support des drapeaux

Basculez les drapeaux g, i, m et s pour affiner votre motif.

Comment utiliser Testeur de regex

1Enter or paste your text or code into the input area.
2Choose the desired operation (format, convert, analyze, etc.).
3Click the action button to process.
4Copy the result from the output area.

Fonctionnalités

✓100% gratuit — sans inscription, sans abonnement, sans publicité
✓Fonctionne entièrement dans votre navigateur — vos données ne quittent jamais votre appareil
✓Rapide et léger — résultats instantanés
✓Multiplateforme — compatible ordinateur, tablette et mobile

Qu'est-ce que Testeur de regex ?

Regular expressions (regex) are a pattern-matching language defined by IEEE POSIX and ECMAScript specifications. They describe search patterns using metacharacters and literals. A Regex Tester lets you evaluate patterns against test strings in real time, highlighting matches and capturing groups.

Comment fonctionne Testeur de regex ?

The tester compiles your pattern into a state machine (NFA/DFA) and applies it to the input string. Flags modify behavior: g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), y (sticky). Match results show position, captured groups, and named groups.

Cas d'usage courants

✓Form validation — emails, phone numbers, postal codes
✓Log parsing — extract fields from structured log lines
✓URL routing — match path patterns in web frameworks
✓Search and replace — batch text transformations

Regex vs String Methods

String methods (includes, indexOf, startsWith) are simpler and faster for exact matches. Regex is necessary for pattern-based matching (e.g., 'all emails in a document'). For simple checks, prefer string methods; for flexible patterns, use regex. Overly complex regex can cause ReDoS (Regular Expression Denial of Service).

Sécurité et confidentialité

This tool runs entirely in your browser. Beware of ReDoS when using regex in production — certain patterns (e.g., nested quantifiers like (a+)+) can cause catastrophic backtracking. Use timeouts or safe regex libraries for user-supplied patterns.

Détails techniques

Specifications: ECMAScript 2024 (MDN Reference), IEEE POSIX. Metacharacters: . * + ? ^ $ { } [ ] \ | ( ). Character classes: \d \w \s \b. Quantifiers: * (0+), + (1+), ? (0-1), {n,m}. Lookahead: (?=...) (?!...). Lookbehind: (?<=...) (?<!...). Named groups: (?<name>...).

Questions fréquentes

What is the difference between greedy and lazy quantifiers?

Greedy quantifiers (*, +) match as much as possible; lazy quantifiers (*?, +?) match as little as possible. Use lazy when you want the shortest match.

How do I test for a whole word?

Use word boundaries: \bword\b matches 'word' but not 'sword' or 'words'.

What are lookahead and lookbehind?

Lookahead (?=...) asserts what follows without consuming it. Lookbehind (?<=...) asserts what precedes. They are zero-width assertions useful for conditional matching.