Zero Snippet

Text diff checker — compare two versions with line-level highlights

Use this free online text diff checker to compare two plain-text documents in a side-by-side diff view: unchanged lines stay aligned, removed lines highlight on the left, and new lines highlight on the right. It fits legal, editorial, and content-ops workflows when you receive “track changes” as two full drafts from email, Word exports, or a CMS. Processing is client-side only—paste or upload UTF-8 .txt per panel, then copy a unified diff for tickets. For source snippets and configs, the code diff checker uses the same line engine with a developer-focused guide. Normalize noisy JSON before comparing API payloads with our JSON formatter & validator.

5 lines

5 lines

2 unchanged−3 removed+3 added

Original
Revised
1Terms of service — summary (draft v1)
1Terms of service — summary (draft v2)
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3Our service may be updated from time to time. We will notify users by email when material changes occur. Continued use constitutes acceptance.
3Our service may be updated periodically. We will notify registered users by email at least 14 days before material changes take effect. Continued use after the effective date constitutes acceptance of the revised terms.
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5Refund requests must be submitted within 7 days of purchase.
5Refund requests must be submitted within 14 days of purchase.

Comparison is line-based. Normalize line breaks or run a whitespace pass first if you only care about wording, not wrapping. For code-oriented snippets and configs, you can also use the code diff checker in the developer tools section.

Why use a browser-based text comparison tool?

Editors, paralegals, and growth teams constantly juggle before and after text that never arrives as a single redlined file. An instant document diff answers “what changed between these two pastes?” without installing desktop compare utilities or uploading confidential drafts to a third party. Because this page never sends your buffers to our servers, you can review NDAs, pricing paragraphs, or internal FAQs on a locked-down laptop.

Pair diffing with cleanup utilities from the same catalog: remove repeated statements using the duplicate line remover, normalize capitalization with the text case converter, and check length limits with the word counter after you merge edits.

How to use this text diff checker (step by step)

  1. Put the original draft in the left panel—the version from legal, the last published FAQ, or an older export. Use Upload .txt if you already saved plain text to disk.
  2. Paste the revised draft on the right. Click Load sample to preview a short terms-style comparison with multiple line edits.
  3. Read the side-by-side table: line numbers restart per column, blank mates show insertions or deletions, and the summary counts quantify unchanged, removed, and added rows.
  4. Optional: click Copy unified diff (with the copy icon) to grab a -/+/ block for Jira, Confluence, or email. Use Clear both when you start a new pair.

Keywords and workflows people search for

Teams look for an online text compare, paragraph diff tool, paste two versions, or contract redline alternative when Word track changes is unavailable. Content strategists diff landing copy; support leads diff macro replies; engineers still prefer the code-oriented diff page for stack traces and YAML. If wrapping or spaces dominate the noise, trim pasted blocks with the whitespace remover before diffing.

Line-based diffing vs word processors and Git

This checker aligns whole lines using a classic longest common subsequence approach. That keeps behavior predictable for policies and email threads, but a one-word edit inside a long line appears as a full line removal and addition. Word-level track changes and semantic legal diff products can look finer for prose; Git remains the system of record for repositories. Use this page when you only have two static strings and need a fast visual answer.

Privacy, limits, and best practices

Nothing leaves your tab during comparison. Each side caps at a few thousand lines to protect browser memory—slice chapters or sections for book-length material. Prefer redacted excerpts when sharing screen recordings. For pattern-based rewrites across one document, our regex tester & debugger complements line diffs when you hunt structural issues rather than pairwise versions.

Related text & string tools

Browse the full text and string tools section on the home page. Highlights:

  • Word Counter — Count words, characters, sentences, paragraphs, and estimated reading time for articles and limits.
  • Text Case Converter — Switch between uppercase, lowercase, title, camelCase, snake_case, and kebab-case in one pass.
  • Duplicate Line Remover — Deduplicate pasted lists with case-sensitive or insensitive matching for clean datasets.
  • Text Reverser — Reverse full text, words per line, or each line—quick puzzles, tests, and obfuscation demos.
  • Find & Replace Tool — Find and replace plain text or regex patterns across long documents without an editor install.
  • Slug Generator — Turn titles into URL-safe, lowercase, hyphenated slugs for blogs, products, and routes.
  • Line Sorter — Sort lines A–Z, Z–A, by length, or randomly to tidy logs, lists, and imports.
  • Whitespace Remover — Trim edges and normalize spaces so pasted content fits forms, CSVs, and code blocks.
  • Text to Binary Converter — Encode text to binary strings or decode binary back to readable characters for learning and demos.
  • ROT13 Encoder & Decoder — Apply ROT13 encode/decode in the browser for quick CTF-style or legacy text tasks.
  • Caesar Cipher Tool — Encrypt or decrypt with a custom Caesar shift—educational and lightweight obfuscation.
  • Word Frequency Analyzer — Rank word counts in pasted text to spot repetition, SEO stuffing, or vocabulary patterns.
  • Email Extractor — Pull every valid email from messy text or HTML into a deduplicated list for outreach prep.
  • URL Extractor — Extract URLs from blobs of text or HTML for audits, archiving, and link inventories.

Frequently asked questions

What is a text diff checker used for?
A text diff checker shows what changed between two plain-text versions—line by line. Teams use it for marketing copy, legal clauses, policy drafts, email threads, and CMS exports when they need a fast before-and-after without opening a full document suite.
Is my text uploaded to your servers?
No. Comparison runs entirely in your browser with JavaScript. Nothing you paste or load from a local file is sent to our backend unless you use another page on this site that explicitly makes network requests.
How is this different from the code diff checker?
Both use the same line-based comparison engine. The Text Diff Checker is framed for prose, policies, and content workflows, while the developer-oriented code diff page emphasizes snippets, configs, and PR-style reviews. Pick whichever page matches your mental model.
Why does one edited word show a whole line as removed and added?
The tool compares whole lines, not individual words or characters. A small change in a long paragraph still replaces that entire line in the alignment. For word-level swaps across a document, use a find-and-replace workflow or specialized prose diff software.
Can I load files instead of pasting?
Yes. Use the upload control beside each panel to load a UTF-8 text file (for example .txt). The file is read locally in your browser and fills that side only.
What does “Copy unified diff” produce?
It copies a plain-text patch-style block: unchanged lines are prefixed with a space, removed lines with a minus, and added lines with a plus—handy for tickets, comments, or archival notes alongside the visual side-by-side view.
Is there a size limit?
Each side is limited to about two thousand lines so the page stays responsive. Split very long documents into sections, or rely on Git or a desktop compare tool for entire books or huge logs.
Will reordering paragraphs look noisy?
Often yes. Line order matters to the alignment algorithm, so moving blocks can appear as many deletions and insertions even when the sentences are identical. Reorder-aware tools exist elsewhere; this page is optimized for quick paste-and-compare of two fixed versions.