Line Filter
Filter multi-line text to show only matching lines — like grep in your browser.
Line Filter is a browser-based grep utility. Paste any multi-line text and instantly filter it by substring, prefix, suffix, or full regular expression. Toggle case sensitivity and invert matching to show non-matching lines — useful for log analysis, data cleaning, and quick searches without leaving your browser.
Frequently Asked Questions
What regex syntax is supported? +
The Regex mode uses JavaScript's native RegExp engine, which supports standard syntax including character classes, quantifiers, anchors, lookaheads, and named groups. The i flag is applied automatically when case sensitivity is off.
What does "Invert match" do? +
Like grep -v, invert match shows only the lines that do NOT match your pattern. This is useful for excluding noise lines from log files or data exports.
Are results updated in real time? +
Yes — the output updates on every keystroke in the pattern field and whenever you change the mode, case sensitivity, or invert options.
Frequently Asked Questions
- It keeps or removes lines based on whether they match a keyword or regex pattern — similar to grep but in the browser.