Regex Tester
Test JavaScript regular expressions with live highlights, capture groups, replace, and split. Flag toggles and common presets included.
1 matches
Uses JavaScript RegExp syntax. Without global (g), only the first match is listed. Replace mode uses $1, $2 for capture groups.
How it works
Set pattern and flags
Type a regex pattern or pick a preset (email, URL, IPv4). Toggle g/i/m/s/u/y flags or edit the flags field directly.
Paste test text
Paste or type sample text. In Match mode, hits highlight in yellow below the input. Capture groups and indexes appear in the results panel.
Replace, split, or export
Switch to Replace to preview substitutions ($1 for groups) or Split to break on the pattern. Copy or download the output.
Why test regex in the browser?
Regular expressions are powerful but easy to get wrong. Regex Tester is part of Easy24’s developer toolbox. Your input stays in this tab for normal use; Easy24 does not upload that content to process it. This tool has no daily free-plan cap; use it as often as you need. Typical flow: Enter a pattern and flags (or use presets), paste sample text, pick Match / Replace / Split, then copy or download results. Matches highlight live in the input panel. Related tools and reverse conversions appear on the page when a follow-up step is common.
Why use this tool
- Live match highlighting
- Capture groups and match indexes
- Match, Replace, and Split modes
- Flag toggles and regex presets
- Up to 200 matches listed
- Unlimited use with no daily cap
Questions
What regex flavor is supported?
JavaScript RegExp as implemented in your browser, not PCRE or Python syntax.
Why only one match without the g flag?
Without global (g), RegExp stops after the first match. Enable g to find all occurrences.
How do capture groups work in Replace?
Use $1, $2, … for numbered groups and $<name> for named groups in the replacement string. $$ inserts a literal dollar sign.
Is highlighted output safe?
Yes. Highlights are React elements, not injected HTML from your regex.
If Easy24 helped, buy a coffee
Tools stay free. A one-time tip is optional and helps keep them running.
When to use Regex Tester
Regex Tester is one of those utilities you open for a few minutes, finish the task, and close without leaving a trail of uploads. Test JavaScript regular expressions with live highlights, capture groups, replace, and split. Developer utilities remove friction from small tasks: formatting, snippets, colors, loaders, and other front-end helpers. Compared with installing a desktop suite only for regex tester, a dedicated page keeps the interface small and the intent obvious. Quota cookies may still track anonymous daily free-plan uses. That is different from receiving your file bytes or pasted text. This page has no daily free-plan cap, so you can run it as often as you need. If a free-plan limit applies, the workspace shows remaining uses before you commit a download, so you are not surprised after a long wait.
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