How to use the Text Diff & Compare Tool
Compare any two text blocks — config files, release notes, log snippets, prompts, emails, contracts, or copied file versions — and see exactly what changed. The Text Diff tool highlights line-level and word-level differences side by side, supports whitespace-insensitive comparison, and runs entirely in your browser so sensitive content never leaves your machine.
What it does
- Side-by-side and inline diff view with line numbers.
- Line-level and word-level change highlighting (added, removed, modified).
- Ignore whitespace, ignore case, and ignore blank lines for noise-free diffs.
- Copy only the added lines, only the removed lines, or the full unified diff.
- Handles CRLF / LF / CR line endings; normalize on demand.
- Works on plain text, code, YAML, JSON, SQL, Markdown, .env, and log output.
When to use it
- Compare two config files before a deploy.
- Review release notes, prompt revisions, or contract drafts.
- Diff two log snippets to spot what changed between runs.
- Check what was edited in a Slack/email reply or document version.
- Verify a test output against an expected baseline when git is not handy.
- Compare two prompts or model outputs during prompt engineering.
How to use it
- Paste the original text on the left and the updated text on the right.
- The diff renders automatically — additions are highlighted green, removals red, and changes show both.
- Toggle word diff to highlight character-level edits inside changed lines.
- Enable Ignore whitespace when only formatting changed; enable Ignore case when casing is irrelevant.
- Use Copy Added, Copy Removed, or copy the full unified diff for tickets and PR descriptions.
- For JSON specifically, use the JSON Diff tool for structural, key-aware comparison.
Tips & pitfalls
- If the whole file looks changed, line endings probably differ — normalize CRLF/LF first.
- Word diff is invaluable for prose and prompts; line diff is better for code and configs.
- Trailing whitespace and tab/space mismatches show as differences unless you ignore whitespace.
- For JSON, key reordering shows as a full rewrite in text diff — switch to JSON Diff for semantic comparison.
- Very large files may be slow on lower-end devices; split into sections if needed.
FAQ
- How do I compare two text files online? Paste each file's contents into the left and right panes. The diff highlights additions, deletions, and modified lines instantly.
- Is this a free text compare tool? Yes — fully free, no signup, no upload. It runs in your browser using the same diff algorithms used by code review tools.
- Can I ignore whitespace and line endings? Yes — toggle Ignore whitespace and normalize line endings to compare only meaningful changes.
- What is the difference between line diff and word diff? Line diff marks whole lines as changed; word diff goes inside a changed line to highlight only the words that differ — better for prose and small edits.
- Is my text uploaded anywhere? No. Comparison is local in your browser. Nothing is sent to a server, logged, or saved.
- Should I use Text Diff or JSON Diff for JSON? Use JSON Diff for structural comparison that ignores key order and whitespace. Text Diff treats JSON as raw characters.
Runs locally in your browser. No uploads. No analytics on pasted text.
