Compare two versions of text

Paste your original and changed versions, and PocketSpry shows you what was added and removed instantly — no sign-up, no upload, and no waiting on a server. It is built for documents, emails, drafts, notes, code snippets, configuration, and any other text you want to compare.

Compare by lines or words

Lines mode compares logical lines and is the best default for documents, code, configuration, and paragraph-level edits. Words mode compares prose tokens and is better for sentence-level changes, where you want to see the individual words that changed.

Added and removed text

Added and removed content is highlighted visually and also marked textually — additions are marked with a plus and removals with a minus — so the difference never depends on colour alone. Unchanged text stays neutral for context.

No differences found

If the two versions are exactly the same, that is a successful result, not an error: the tool reports “No differences found”. A change in spacing or capitalization is a real difference and is shown as one.

Exact comparison

This is an exact text comparison. The tool does not rewrite, normalize, trim, correct spelling, change case, collapse whitespace, or interpret meaning — it compares your text exactly as written, at the granularity you choose.

Private and browser-local

Both versions of your text are compared locally in your browser. They are not sent to PocketSpry’s AI service, and neither your text nor the resulting diff is sent to analytics.

Large comparisons

Very large comparisons may take longer, so the comparison runs in the background and stays entirely in your browser. Extremely large or almost-entirely-different inputs may hit a time limit; comparing smaller or more similar text resolves it.

Text diff vs AI comparison

This is a deterministic, exact text comparison — the same input always produces the same diff. It is not an AI meaning or similarity analysis, and it does not judge whether the two versions mean the same thing.

Frequently asked questions

What does Text Diff Checker do?: It compares two blocks of text and highlights what was added, removed, and unchanged, in your browser.
What is a text diff?: A diff is a comparison of two versions of text that shows exactly what changed between them.
What is the difference between Lines and Words mode?: Lines mode compares whole lines (best for documents, code, and configuration). Words mode compares individual words (best for sentence- and prose-level edits).
Does it show added text?: Yes — added content is highlighted and marked with a plus.
Does it show removed text?: Yes — removed content is highlighted and marked with a minus.
What happens if the texts are identical?: It reports “No differences found” as a successful result — not an error.
Can one side be empty?: Yes. Comparing blank text against real text is a valid diff.
Can both sides be empty?: No — with nothing to compare, the tool asks you to enter text in at least one field.
Does it ignore capitalization?: No. A change in capitalization is treated as a difference.
Does it ignore whitespace?: No. Spacing changes are treated as differences.
Does it correct spelling?: No. It compares your text exactly as written.
Does it compare meaning?: No. It is an exact deterministic text diff, not an AI meaning or similarity analysis.
Can I compare code?: Yes, especially in Lines mode — though it is a general text comparator, not a language-aware code parser.
Does it merge changes?: No. It shows differences; it does not merge or edit your text.
Does it upload my text?: No. Your text is compared locally in your browser.
Is it sent to AI?: No. This tool does not use AI and makes no server or AI call.
Does PocketSpry send my text or diff to Plausible?: No. Neither your text nor the resulting diff is sent to analytics.
What’s the maximum input size?: 100,000 characters per side.
Is the output AI generated?: No. It is computed deterministically in your browser.