How do I compare two texts online?
Paste the original text in the left box and the modified text in the right box, then click Compare Texts. Added lines show in green and removed lines in red, with a count of changes.
Is this text diff checker free?
Yes. It is free with no signup, and all comparison happens locally in your browser.
What do the colors mean?
Green marks lines present only in the modified text (additions); red marks lines present only in the original (deletions). Unchanged lines appear plain.
Does it count added and removed lines?
Yes. The summary line reports how many lines were added, removed, and the total number of changes.
Can I compare code or config files?
Yes. Line mode works well for source code, JSON, SQL, and configuration files where each line is a meaningful unit.
Will my text stay private?
Completely. The two texts are compared in your browser and never uploaded to a server.
Does it support word-level diff?
This tool compares by line, which is best for code and whole-file reviews. For prose, paste smaller chunks to isolate edited lines.
Can I compare very long texts?
Yes. For readability, compare in sections so each report stays focused on a manageable block of changes.
What text can I paste?
Any plain text — code, documents, emails, or notes. The widget handles standard characters and line breaks.
Is there a size limit?
There is no fixed limit from the tool; very large inputs depend on your device memory, but typical files compare instantly.
A text diff checker compares two blocks of text and shows exactly what changed between them. It highlights added lines in one color and removed lines in another, so you can see a revision at a glance instead of reading both versions word by word. Our online diff tool runs entirely in your browser: paste the original on the left, the modified version on the right, and the differences appear instantly. There is nothing to install and no server ever stores your text.
Developers use a diff checker to review pull requests and spot accidental edits before committing. Writers compare draft versions of an article to confirm a collaborator's changes. Support engineers diff configuration files to find the one setting that broke a deployment. Students compare essay revisions against feedback, and translators verify that a localized string still matches the source. When the text you are comparing is structured data, the JSON formatter or the SQL formatter helps you normalize layout first so the diff shows real changes, not whitespace noise.
Most quick checks compare by line, which is fast and readable for whole-file reviews. When a single long line changed, a line diff marks the entire line — useful, but noisy. A word or character diff zooms into that line and highlights only the edited words, which is better for prose and legal text. Pick line mode for code and config, and word mode when you care about precise edits inside a paragraph. Our tool uses line mode for clarity; for finer control, paste smaller chunks.
Command-line tools like diff and git diff are powerful but require a terminal and a repo. Desktop apps add folders and merge support but need installation. A browser-based diff checker wins for a one-off comparison of two snippets you copied from an email or chat, especially when the content is confidential and you would rather not paste it into a random website. It stays on the page and disappears when you close the tab.
Trim trailing whitespace before comparing so the diff is not flooded with false positives. Compare normalized text — same line endings, no extra blank lines — to surface only meaningful edits. For very long files, compare in sections so each report stays readable. Keep the original on the left and the new version on the right; a consistent order makes the added/removed colors predictable. The text case converter is handy when casing differences are drowning out real edits.
Everything is computed locally in JavaScript. Your two texts never leave the browser, which matters when you are comparing customer data, source code, or unpublished writing. There is no tracking script on the widget and no upload step, so closing the tab ends the session completely.
A diff is only useful if you act on it. After comparing, read the summary counts first — a large block of removals with a small addition usually means a paragraph was rewritten rather than deleted, and a balanced count suggests a light edit. When the change is a configuration file, paste the diff into your commit message so reviewers see the intent without opening the file. For documentation, keep the old and new versions side by side while you rewrite so no sentence is accidentally dropped. If the text is long, compare it in logical chunks — by heading, then by section — so each report stays short enough to scan in one glance. The Lorem Ipsum generator is handy when you need placeholder text to test the tool itself, and the HTML entity encoder cleans markup before a comparison so entities do not create fake differences.
