Text Diff
Free text diff online tool to compare two texts line by line in your browser. See added, removed, and unchanged lines instantly. No upload, no account.
Runs locally in your browser. Your input is not uploaded to DevToolMate servers.
Developer Quick Tips
- Paste original and revised text; added lines show +, removed lines show -, unchanged lines show space prefix.
- Each input is capped at 8 MB; split large files into smaller chunks to stay within limits.
- Whitespace and line breaks are preserved exactly as typed, so formatting differences appear in the diff output.
- Export or copy the diff output for code review, testing, or documentation workflows without leaving your browser.
- Line-based comparison means every line is compared as a whole unit; no word-level or character-level matching is performed.
Frequently asked questions
What is a text diff online tool?
A text diff tool compares two texts line by line and shows which lines were added, removed, or stayed the same. Text Diff runs entirely in your browser for free with no account needed.
How do I compare two texts online for free?
Paste your original text and revised text into Text Diff, then press Ctrl/Cmd + Enter or click the compare button. The tool runs entirely in your browser and is free with no account required.
What do the +, -, and space prefixes mean in a diff?
In a line diff, + means a line was added, - means a line was removed, and a space prefix means the line is unchanged. This makes it easy to spot exactly what changed between two texts.
Does Text Diff upload my data to servers?
No. Text Diff is a browser-local tool. Your input stays on your device for the current session and is never uploaded to DevToolMate servers or external APIs.
Is there a size limit for comparing texts?
Yes. Each input (original and revised) is capped at 8 MB. For larger files, split them into smaller chunks and run multiple comparisons.
Does Text Diff ignore whitespace or reorder lines?
No. Text Diff preserves whitespace and line order exactly as typed. Every space, tab, and line break appears in the output, so formatting differences are visible.
Will my comparison be saved after I close the tab?
No. Input stays in memory only while the tab is open. Closing the tab clears all data. Theme preference is stored locally but is not tool input.
Can I use Text Diff to compare JSON or code files?
Text Diff works on any plain text, including code and JSON. For structured JSON comparison with semantic awareness, use the json-diff tool instead.
Related tools
- JSON Diff: Compare JSON files and spot differences online with canonical formatting and line-oriented diff. Free tool runs in your browser, no upload, no account.