How to compare two texts
- 1Paste the original text into the left box and the changed text into the right box. To compare two files, open each one in an editor and copy its contents. Click Load sample to see an example.
- 2Click Compare. The tool opens a diff view with removed lines highlighted on the left and added lines on the right.
- 3Switch between Side by side and Inline layouts, and tick Ignore trailing whitespace to hide differences that are only spaces at the end of a line.
- 4Read the +added and −removed line counts at the top, and use the overview ruler on the right edge to jump between changes.
- 5Both sides stay editable in the diff view. Click Edit texts to return to the plain boxes, or Swap sides to flip original and changed.
How a diff checker works
A diff checker compares two pieces of text and shows the smallest set of changes that turns the first into the second. It finds the longest run of lines the two share and marks everything else as removed from the original or added in the new version. Inside a changed line it goes a step further and highlights the exact characters that differ, so a single changed word or a stray comma is easy to spot.
This tool uses the same diff engine as the VS Code editor. That makes it a capable text diff for prose, and a handy code diff for source files, JSON, SQL, YAML and config files, because lines are compared exactly and indentation changes are visible. The editor is only downloaded when you click Compare, so the page stays light until you need it.
Use the side-by-side view when you want to read the old and new versions in parallel, and the inline view when the changes are small and you want to see them in one column, like a Git patch. The ignore-whitespace option hides lines that differ only in trailing spaces, which is useful when line endings or editor settings changed.
Use it as a diff online tool or a difference checker online that never uploads your content. Both texts are compared inside your browser tab, so it is safe to use with private documents, credentials in config files or unreleased code. Close the tab and nothing remains.
When developers compare text
Reviewing config changes
Compare two versions of an .env file, a Nginx config or a Kubernetes manifest to see exactly what changed between environments.
Checking code without Git
Paste two snippets from a ticket, a chat or a CMS to see what differs when there is no repository to run git diff on.
Editing documents
Compare two drafts of a contract, article or README to see every edit a collaborator made.
Debugging API output
Paste two JSON responses, ideally formatted first, to spot the field that changed between calls.
Frequently asked questions
How do I compare two files online?
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Open each file in a text editor, copy the contents into the two boxes and click Compare. The files are not uploaded; everything stays in your browser.
Does the diff checker show changes inside a line?
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Yes. Changed lines are paired up and the characters that differ are highlighted more strongly, so you can see exactly which words changed.
Can I ignore whitespace differences?
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Tick Ignore trailing whitespace in the diff view to hide lines that differ only in spaces at the end. Differences in leading indentation are still shown.
Is there a size limit?
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There is no fixed limit, but very large inputs of many thousands of lines can make the diff slower, depending on your device.
Is my text sent to a server?
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No. The comparison runs locally in your browser, so private text, keys and code stay on your device.
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