Compare Text
Compare two texts online and see every change highlighted. Choose character, word, or line detail and ignore whitespace or case. Free, and nothing is uploaded.
Files never leave your browser.
About Text Diff
Compares two pieces of text and highlights what changed. Computes a character, word, or line-level diff in your browser. Nothing is uploaded, even for large inputs.
How to use
- Paste or drop your first version into the left editor (or use Load file to read a local file).
- Paste the second version into the right editor. Additions, deletions, and unchanged regions appear inline.
- Adjust granularity (Character, Word, Line) and the ignore options under Options to tune what counts as a change.
Try a sample
Loads a short pair of sentences with small edits. Useful for seeing how granularity affects the highlighting.
What this tool doesn't handle
- Moved blocks of text are shown as a deletion in the original location plus an insertion at the new location. There is no move detection.
- For files larger than a few megabytes the line-level granularity is most responsive; character-level diffs on huge inputs can be slow.
Frequently asked questions
Do my files ever leave my browser?
No. Every comparison runs locally in your browser. Nothing you paste, drop, or load is uploaded to a server; the tool keeps working even if you go offline after the page loads.
Is this tool free to use?
Yes. All DiffResolver tools are free, with no account, sign-up, or installation. Because processing happens on your device, there are no server-imposed usage limits.
Can I ignore whitespace or capitalization when comparing text?
Yes. Open Options and enable Ignore whitespace or Ignore case. The diff recomputes instantly, so you can toggle them to check which differences are purely cosmetic.
What is the difference between character, word, and line granularity?
Granularity sets the smallest unit the diff reports. Character mode pinpoints single-letter edits, Word mode groups changes into whole words, and Line mode treats whole lines as changed, which is the fastest choice for large files.
Can I compare two text files without copying and pasting?
Yes. Use the Load file button on either editor, or drag and drop a file onto it. The file is read locally and never uploaded.
Is there a file size limit?
No server limit applies, because nothing is uploaded. The memory of your device sets the practical limit. Above 10 MB for text, 40 MB for images, 100 MB for documents, or 500 MB for archives, the tool warns you that the work can be slow, but it never blocks the file.
Does this tool work offline?
Yes. The browser keeps a copy of the tool after the first visit, so a page you opened before still works without a network. You can also install DiffResolver as an app from the browser menu. Installation stays optional; the site works the same in a normal tab.
Where is my data stored?
Your files are stored nowhere. They stay in the memory of the page and are gone when you close the tab. Only what you save yourself stays in this browser: a snapshot, your tool options, and your theme. To remove it, open Settings and select Clear all local data.