Compare two texts and see every difference instantly
A free online diff checker for text, code, JSON and CSV. Paste both versions, and every addition, deletion and edit is highlighted in place — without an account, and without your text ever leaving your browser.
Add text to both panels to see the differences appear here.
The short answer
Text Compare is a free online diff tool that highlights the differences between two blocks of text. Paste the original on the left and the revised version on the right, and additions, deletions and modified lines are marked immediately. Unlike most online comparison tools, the entire comparison runs in your browser using JavaScript, so the text is never transmitted to or stored on a server — the page keeps working even if you disconnect from the internet. It supports side-by-side, unified and track-changes views, line, word and character precision, and export to plain text, unified diff patch or PDF, all without an account.
Why use this diff checker
Everything below is available immediately, for free, with no account and no usage cap.
Nothing leaves your browser
The comparison runs locally in JavaScript. Your text is never uploaded or stored, which makes it safe for contracts, credentials and unreleased work.
Three ways to read the result
Switch between side-by-side, unified and track-changes views. All three are free here, and none of them need an account.
Line, word or character precision
Flag whole lines for code, highlight individual words for prose, or drop to character level to catch a single transposed digit.
Share without an account
Share links pack both documents into the part of the URL after the # symbol, which browsers never transmit to a server. The recipient decodes it locally.
Export anywhere
Copy the result, download a readable report, generate a unified diff patch that Git understands, or print straight to PDF with the colours intact.
Built for the keyboard
Compare with Ctrl+Enter, step through differences with J and K, swap sides with Ctrl+Shift+S. Press ? at any time for the full list.
How to compare two texts
Five steps, about a minute.
- 1
Add the original
Paste your first version into the left panel, or drag a file straight onto it. Files are read locally and never uploaded.
- 2
Add the revision
Paste the second version into the right panel. The comparison updates as you type, so you rarely need to press anything.
- 3
Tune what counts as a change
Ignore case, whitespace, punctuation or blank lines so formatting noise disappears and only the differences you care about remain.
- 4
Step through the differences
Removals appear in red, additions in green and edits in amber. Use the previous and next controls to walk every change in order.
- 5
Keep the result
Copy it, download a report or patch file, print it to PDF, or generate a share link for a colleague.
Want more detail? Read the full step-by-step guide.
How it compares to other online diff tools
The features most comparison sites put behind a subscription are the ones this tool gives away.
| Capability | This tool | Typical online diff tool |
|---|---|---|
| Where your text is processed | Entirely in your browser. Works offline once the page has loaded. | Often posted to a server for processing. |
| Unified and inline views | Included, free. | Frequently reserved for paid plans. |
| Word and character precision | Included, free. | Frequently reserved for paid plans. |
| Sharing a comparison | A link that carries the content in its fragment. No account. | Usually needs a sign-in and server-side storage. |
| Account required | Never. | Commonly required for the useful features. |
| Export formats | Plain-text report, unified diff patch, print to PDF. | PDF export is often a paid feature. |
Who uses a text comparison tool
Any time two versions of the same thing need to be reconciled.
Developers reviewing changes
Compare two revisions of a config file, a stack trace or a generated payload without committing anything or leaving the browser.
Writers and editors
See exactly which sentences an edit touched. Word-level precision and the track-changes view make prose revisions easy to read.
Legal and contract review
Check a returned draft against the version you sent. Because nothing is uploaded, privileged material stays on your machine.
Data and operations teams
Diff two CSV exports or API responses to find the rows and fields that moved between runs.
Students and researchers
Compare drafts, citation lists or transcripts, and confirm which version contains the passage you are looking for.
Support and QA
Put an expected output next to the actual one and pinpoint the character where they diverge.
Specialised comparison modes
Frequently asked questions
Answers to what people most often ask about comparing text online.
How do I compare two text files online?
Paste your original text into the left panel and the revised text into the right panel, then press Compare. Every added, removed and modified line is highlighted side by side, with changed words picked out inside each line. You can also drag a file straight onto either panel instead of pasting.
Is it safe to compare confidential or sensitive text here?
Yes. Text Compare runs the entire comparison in your browser using JavaScript, so the text you paste is never uploaded, transmitted or stored on any server, and no account is required. You can confirm this by disconnecting from the internet after the page has loaded: the comparison keeps working offline. The site does load analytics and advertising, which measure page visits and fund keeping the tool free, but those services never receive the content you compare, and session replay is explicitly blocked from the editors and results.
What is the difference between line, word and character comparison?
Line precision marks a whole line as changed if anything in it differs, which is best for code and structured data. Word precision highlights only the words that changed inside a line, which is best for prose and proofreading. Character precision pinpoints individual characters, which is best for catching typos, transposed digits and subtle formatting changes.
Can I ignore whitespace, capitalisation or blank lines?
Yes. The comparison settings let you ignore case, collapse repeated whitespace, trim leading and trailing spaces, skip blank lines, ignore punctuation, and sort lines before comparing. Sorting is useful when you need to compare two unordered lists and only care about which entries exist.
Is there a file size or usage limit?
There is no account limit and no daily cap. The practical ceiling is your device's memory, since everything runs locally. Documents of several thousand lines compare in a few milliseconds, and unchanged sections are collapsed automatically so large results stay readable.
Can I share a comparison with someone else?
Yes, and it does not require an account. The Share button compresses both texts into the link's fragment, the part after the # symbol. Browsers never send that fragment to a web server, so the link reconstructs the comparison entirely on the recipient's device while still keeping the content off our infrastructure.
Does this work for code, JSON and CSV files?
Yes. Dedicated modes are available for code, JSON and CSV. The JSON mode can pretty-print both sides first so that formatting-only differences disappear and you see genuine key and value changes, and the CSV mode can sort rows so reordered exports still line up.
How do I export or save the comparison result?
You can copy the result to your clipboard, download it as a plain text report, download a standard unified diff patch file that Git and other tools understand, or use Print to save a clean, colour-accurate PDF.