Built for anyone who needs to compare text — privately and instantly
TextFileCompare.com is a free, browser based diff tool. No installation, no login, no server upload. Your files never leave your device — the entire comparison runs locally in your browser.
Why we built this
Text comparison is a task that comes up constantly and yet the tools available for it have always felt like they were designed for a very narrow audience. Desktop diff tools require installation, administrator permissions, and configuration before you can compare a single file. Many online tools upload your text to a server, which is a non-starter when the content is confidential. And command-line tools like diff produce output that's hard to read unless you already know how to parse unified diff format.
We built TextFileCompare to sit between those extremes: as capable as a desktop diff app, but as accessible as opening a browser tab. No installation. No account. No upload. Open the page, paste or load your files, and compare in seconds, on any device.
The privacy side wasn't an afterthought. When you're comparing a configuration file that contains credentials, a legal contract, or proprietary source code, you shouldn't have to trust a server you know nothing about. TextFileCompare runs the entire comparison algorithm locally in your browser using JavaScript. Your text never leaves your machine. You can verify this yourself by opening the browser's Developer Tools, going to the Network tab, and watching during a comparison you'll see zero outbound requests carrying your content. If you want to be completely certain, disconnect from the internet after loading the page the tool still works, because it doesn't need a network connection to run the diff.
Who uses TextFileCompare
Text comparison isn't a niche developer task it comes up across almost every field that deals with documents or code. Here are the most common ways people use the tool:
- Software developers comparing two versions of a function, reviewing a patch file outside of their IDE, or checking what a build script changed in a config before deploying.
- DevOps engineers and sysadmins diffing configuration files between environments
nginx.conf,.env,docker-compose.ymlor verifying that a change was applied correctly across servers. - Writers and editors comparing two drafts of an article or report to see every added, removed, or changed sentence without reading both documents from top to bottom manually.
- Legal and compliance professionals redlining contracts, comparing policy documents, or verifying that standard clauses appear verbatim in an executed agreement.
- QA engineers and testers comparing expected output files to actual output, or diffing two API responses to spot unexpected differences.
- Students and academics tracking how an essay developed across drafts, comparing a transcription to a source, or spot checking translated text against an original.
- Anyone on a managed or locked-down computer where installing desktop software requires IT approval — a browser-based tool works instantly, on any machine, with no installation at all.
The common thread: people who need to answer the question "what exactly changed between these two things?" and want an answer quickly, without barriers.
What the tool does
TextFileCompare uses the Myers diff algorithm the same algorithm used by Git to find the minimum set of additions and deletions that separate two texts. The result is shown as a side-by-side comparison with colour coding: added content in green, removed content in red, unchanged content in neutral. Word-level highlighting within changed lines shows you exactly which words changed, not just which lines.
Two panels with synchronized scrolling, live line and character counts, and chunk navigation to jump between differences with keyboard shortcuts or buttons.
Highlights individual words or characters that changed within each line not just which lines changed. Especially useful for proofreading prose or spotting single value changes in config files.
Accept changes left-to-right or right-to-left with one click. Smart merge applies a patch based algorithm for more nuanced combining of changes. The result is editable and exportable.
Auto-detects JavaScript, TypeScript, Python, PHP, HTML, CSS, JSON, XML, SQL, YAML, Shell, Java, C/C++, Markdown, INI, and plain text from the file extension or content.
Inline search across both panels simultaneously with case-sensitive and regex modes. Replace one match or all matches in the focused panel. Open with Ctrl+F.
Download a unified diff patch file compatible with git apply, generate a self contained HTML diff report for sharing, copy the diff to clipboard, or save either panel as a file.
Drop any text based file onto either panel. Supported formats include .txt, .js, .py, .json, .php, .yaml, .sql, .md, and many more. Language is auto detected from the extension.
The diff algorithm runs in your browser no data is transmitted to our servers at any point. No account needed. No content logged. Works offline once the page has loaded.
Our approach to privacy
We believe a tool that asks you to trust it with sensitive content should be transparent about exactly how that content is handled. Our approach is simple: we handle it by not handling it at all.
The comparison algorithm runs in your browser. The text you enter is never transmitted to our servers. We use localStorage to remember your preferences theme and language selection but that data stays on your device and contains none of your file content. The only third-party code running on the page is advertising and analytics, which operate on usage patterns, not content. Our full privacy policy is here.
Who we are
TextFileCompare.com was built by a small team of independent developers who believe useful tools should be free, fast, and privacy respecting. We focus on performance, usability, and security making the tool work seamlessly on both desktop and mobile, across all modern browsers, without requiring any setup or installation from the user.
The tool is actively maintained. When something breaks or a better approach exists, we update it. If you find a bug or want to suggest an improvement, we genuinely want to hear from you.
Get in touch
Have feedback, a feature request, or found a bug? Visit our contact page or email us directly at admin@textfilecompare.com. We read everything.
See the full list of features on the features page.
New here? Read the step-by-step how-to guide.
Read our blog for guides on text comparison and diff tools.
Read our privacy policy — we store nothing.