A free, private Diffchecker alternative
Diffspot gives you the advanced comparison features without monthly limits or an account, and your files never leave your device.
Diffchecker is a popular, capable comparison tool. Its free web plan limits several everyday features to a few uses per month, and keeping files on your device requires its paid desktop app. Diffspot is built around the opposite defaults: everything is free and unlimited, and every comparison runs locally in your browser.
Diffspot vs Diffchecker at a glance
| Feature | Diffspot | Diffchecker |
|---|---|---|
| Price | Free, every feature | Free plan with limits; Pro + Desktop $15/user/month |
| Where comparisons run | In your browser, on all plans | Web plans: "Your files never leave your device" not included (Desktop app only) |
| Works offline | Yes, after the first visit | Desktop app only |
| Unified view, real-time diff, merge | Unlimited | Limited uses per month on the free plan |
| Syntax highlighting | Unlimited, 40+ languages auto-detected | Limited uses per month on the free plan |
| Ignore whitespace / custom ignore rules | Unlimited, plus masks for dates, UUIDs, numbers and regex | Limited uses per month on the free plan |
| Redline (tracked-changes) view | Yes | Not on Basic or Pro plans |
| Folder comparison | Yes | Not on Basic or Pro plans |
| PDF, Word, PowerPoint | Yes (text) | Yes |
| Excel and CSV | Yes, with key-column matching | Yes |
| Image comparison | Side by side, slider, fade, flicker, difference | Yes |
| Share a comparison | Link containing the texts (no upload) | Saved to their cloud and shared by link |
| OCR for scanned documents | No | Yes (basic on free plan) |
| AI summaries | No | Limited on free plan |
| Ads | Yes, isolated in sandboxed frames | Yes on free plan; ad-free on Pro |
Why switch
Your files stay on your device
Contracts, source code, payroll spreadsheets and customer exports shouldn't need to visit a server to be compared. Diffspot downloads its engine once and processes everything locally. That's true for every file type and on every visit, with no desktop app to install.
No monthly limits
Switching to unified view, ignoring whitespace, merging a change or turning on syntax highlighting never counts against a quota. Large files are fine too: hundreds of thousands of lines compare in about a second.
Built for reading changes
Unchanged sections fold away, moved blocks are recognized as moves, and changed words are highlighted inside each line. Step through changes with F7, and switch between side-by-side, unified and redline views.
When Diffchecker may suit you better
If you need OCR for scanned PDFs, AI summaries of changes, or comparisons saved in the cloud with comments for your team, Diffchecker offers those and Diffspot doesn't.
Questions
Is Diffspot a good free alternative to Diffchecker?
If you want unlimited advanced features for free, and you want your text and files to stay on your device, yes. Diffspot includes unified view, merging, syntax highlighting, ignore rules, redline, folder comparison and exports with no monthly limits. Diffchecker offers things Diffspot doesn't, such as OCR, AI summaries and cloud-saved comments.
Does Diffspot upload my files?
No. Every comparison runs in your browser with a Rust engine compiled to WebAssembly. You can check in your browser's network panel, or disconnect from the internet after loading the page.
Can I save comparisons like on Diffchecker?
Diffspot deliberately has no server-side storage. Use Share to get a link that contains the texts, or export a patch, an HTML report or a PDF.
Try Diffspot now: no sign-up, nothing to install.