Free Text Diff Compare
Paste two versions of any text and instantly see the differences highlighted with additions, deletions, and changes. Switch between four diff modes — character, word, line, and sentence — to get exactly the level of detail you need. Powered by jsdiff, the most widely used JavaScript diff library, implementing the Myers diff algorithm (the same algorithm used by git). All processing happens locally in your browser — no signup, no server, no data sent anywhere.
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Why Use a Text Diff Tool?
Comparing two versions of text by eye is slow and error-prone — you will miss subtle word changes, deleted sentences, and rearranged paragraphs. This text diff tool highlights every addition, deletion, and change instantly, so you can see exactly what is different between two versions without reading both line by line.
The tool is powered by jsdiff, the most widely used JavaScript diff library. It implements the Myers diff algorithm — the same algorithm used by git — to produce minimal, accurate diffs. Choose from four comparison modes: character diff for spotting typos, word diff for general text comparison, line diff for code and config files, and sentence diff for reviewing paragraph-level edits. Green highlights show additions, red with strikethrough shows deletions.
Use it to compare drafts of documents, review AI-generated text against the original, check configuration changes, proofread edits, or verify what changed between two API responses. All comparison happens locally in your browser — your text is never uploaded or stored anywhere.
Four Diff Modes for Every Use Case
Not all text comparisons are the same. A single typo needs character-level precision, while a document rewrite is easier to review sentence by sentence. This tool gives you four diff modes so you can match the comparison granularity to the task.
Character diff compares every individual character, making it ideal for catching typos, spacing issues, and subtle formatting changes. Word diff (the default) treats each word as a unit, which is the most natural way to compare edited prose, articles, and general text. Line diff compares entire lines at once, mirroring how git diff works — best for source code, JSON, YAML, and configuration files. Sentence diff treats each sentence as a token, giving you a high-level view of structural changes in paragraphs and documents.
All four modes use the same underlying Myers diff algorithm to find the minimum set of changes, ensuring accurate and optimal results regardless of which mode you choose.
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How It Works
Paste or type the original text on the left and the modified text on the right.
Choose a diff mode: character, word, line, or sentence.
Click Compare and see differences highlighted instantly.
Key Features
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Use Cases
Frequently Asked Questions
Is this text diff tool completely free to use?
Yes, it is 100% free with no limits on the number of comparisons, no signup, and no feature restrictions. Some diff tools charge for features like side-by-side view or export. This tool gives you full character-level, word-level, line-level, and sentence-level diffing at zero cost because all processing runs locally in your browser with no server involvement.
Is my text sent to a server when I compare documents?
No. All diffing happens entirely inside your browser using the jsdiff library — your text never leaves your device. There are no API calls, no cloud processing, and no logging of your content. This is essential when comparing confidential documents, legal contracts, proprietary code, or any text containing sensitive information you would not want uploaded to a third-party diff service.
What is jsdiff and the Myers diff algorithm?
jsdiff is the most widely used JavaScript text differencing library. It implements the Myers diff algorithm, described in the 1986 paper "An O(ND) Difference Algorithm and its Variations" by Eugene W. Myers. This is the same algorithm used by git to compute diffs. It finds the minimum set of insertions and deletions needed to transform one text into another, producing optimal, deterministic results — the same two inputs always yield the same diff output.
What diff modes are available and when should I use each one?
The tool offers four diff modes. Character mode compares every individual character — ideal for spotting typos, single-letter changes, and whitespace differences. Word mode (the default) treats each word as a unit — best for general text editing, proofreading, and document comparison. Line mode compares entire lines at once — useful for code, configuration files, and structured data where changes happen line by line. Sentence mode treats each sentence as a unit — great for reviewing paragraph-level rewrites where you want to see which sentences were added, removed, or changed.
Can I use this to compare code or programming files?
Yes. You can paste any text including source code in any programming language. The diff is computed on the raw text content and works equally well with Python, JavaScript, HTML, CSS, SQL, JSON, YAML, or any other format. For code, try line diff mode — it mirrors how git diff works. The comparison is not syntax-aware (it does not understand language grammar), but it accurately highlights every difference between the two versions, which is what you need for code review and change tracking.
Can I compare large documents or very long texts?
Yes. The tool handles documents of typical working size (articles, contracts, code files, configuration files) without issues. For very large texts above 100KB, the comparison may take a moment longer to compute. Documents above 500KB may cause noticeable slowdown on older devices. If you need to diff very large files (multiple megabytes), a desktop tool like VS Code diff or the command-line diff utility will perform better.
How is this different from using git diff or VS Code diff?
git diff and VS Code diff require you to have files in a repository or open in an editor. This tool is faster for ad-hoc comparisons — paste any two pieces of text from anywhere (emails, chat messages, documents, API responses, clipboard contents) and see the differences instantly. It also gives you more flexibility: switch between character, word, line, and sentence diff modes to get the right level of detail. No files to create, no repository needed, no software to install.
Can I use this to review AI-generated text against my original?
Yes, this is a popular use case. Paste your original text on one side and the AI-edited or AI-generated version on the other. The diff will highlight exactly what the AI changed — added sentences, removed words, rephrased passages — so you can accept or reject each change deliberately rather than blindly using the AI output. Try sentence mode to see paragraph-level rewrites, or word mode to catch every individual word change.
Does this tool work for comparing translated versions of text?
You can paste two versions of a translation to see what changed between revision rounds, but the tool compares raw text — it does not understand language semantics or alignment between source and target languages. It is most useful for comparing two versions of the same translation (draft 1 vs. draft 2) rather than comparing an English original against a Spanish translation, where almost every word would show as a change.
Limitations
- Best suited for plain text comparison
- Does not support syntax-aware diffing for code
- Very large texts may slow the comparison