Is my text sent to any server?

No. All regex matching and replacement happens entirely in your browser. Your text never leaves your device.

Which regex syntax is supported?

JavaScript regular expression syntax is supported, including flags g, i, m, s and u. Invalid patterns show an error message instead of silently failing.

Can I test capture groups?

Yes. Every match is listed with its start index and all capture groups, and you can use $1, $2 etc. in the replacement field.

Back to Ercc

正则表达式测试器

用实时高亮测试你的正则表达式。 100% 在浏览器中运行。

Format & Beautify Validate Syntax Minify No Data Uploaded

Pattern

Flags

Test Text 0 chars

Match Preview

Enter a pattern and test text to see highlighted matches here.

Replace

How It Works

Paste or Load JSON

Paste JSON text, use the Paste button, or load a .json file from your device.

Format or Minify

Click Format to beautify with proper indentation, or Minify to compress it.

Copy & Use

Copy the result to clipboard. If JSON is invalid, you'll see the exact error location.

为什么使用 Ercc 正则表达式测试器？

Format & validate

Pretty-print with adjustable indentation, or minify for production. Instant error detection.

No data leaves your browser

Safe for API keys, tokens, and config files. Nothing is uploaded.

Copy with one click

Copy formatted or minified output to clipboard instantly.

Frequently Asked Questions

Is my JSON data sent to any server?

No. All formatting, validation, and minification happens entirely in your browser. Your data never leaves your device.

What JSON size can it handle?

There is no size limit. It can handle megabytes of JSON data instantly, limited only by your browser's memory.

Does it show error locations?

Yes. If your JSON has syntax errors, the error message will describe exactly what went wrong and where.