Frequently asked questions

No — and you can verify it yourself. Open DevTools → Network tab, then convert a file. You'll see zero upload requests. Every conversion runs in your browser using WebAssembly. There is no upload endpoint, no temporary storage, and no server that ever sees your files.

Yes. Contracts, medical records, private photos — none of it travels over the network. The only server communication is Stripe for payments and Google OAuth for sign-in. File processing doesn't touch a server at all.

No. Our server has no file upload endpoint. There is no S3 bucket, no processing queue, and no logging of file content. When you close the tab, the converted file exists only in your local Downloads folder.

Anonymous page-view counts (no file content, no IP addresses tied to files), your email if you create a Pro account, and Stripe payment data processed entirely by Stripe. That's it.

43+ formats across four categories:

• Images: JPG, PNG, WebP, AVIF, GIF, BMP, TIFF, HEIC, SVG, ICO, EPS, ARW
• Video: MP4, MOV, AVI, MKV, WebM, WMV, GIF (animated)
• Audio: MP3, WAV, OGG, FLAC, M4A, AAC, OPUS
• Documents: PDF, DOCX, PPTX, Pages, EPUB, SVG

Free: up to 10 MB per file. Pro: up to 500 MB per file — enough for 4K video clips and large RAW photos. Upgrade to Pro to unlock the higher limit.

Free accounts handle up to 5 files per batch. Drop them all at once and they convert in parallel. Pro is unlimited — hundreds of files, no cap.

Free-tier image conversions get a subtle formatdrop.com watermark applied locally via the Canvas API — no server involved. Pro removes it entirely. Video and audio conversions are watermark-free on all plans.

No. Watermarks only apply to image conversions on the free tier. Video and audio output is always clean, on every plan.

Head to the Pro page and pick monthly ($9.99/mo) or yearly ($49/yr). Payment is processed by Stripe. You'll get a magic-link email — click it and Pro is active instantly. No account required to purchase.

Yes, any time. Open your account page, click Manage billing, and you're in the Stripe portal. Cancel, update your card, or download invoices in seconds. You keep Pro access until the end of your current billing period.

No. Convert files right now — no sign-in needed. An account is only useful for Pro users who want their subscription synced across multiple devices.

The first conversion on a fresh page load downloads the WebAssembly codec (the compiled C library that does the actual converting). Depending on your connection, that takes 5–20 seconds. After that, the engine stays in memory and everything is near-instant.

Any modern browser with WebAssembly support: Chrome 57+, Firefox 52+, Safari 11+, Edge 79+. For best performance with large video files, Chrome or Firefox is recommended.

Refresh the page — this reloads the WebAssembly engine and clears any stuck state. If a specific file keeps failing, the file's internal encoding may not match the format extension. Try re-exporting or re-saving it in another app first.

FormatDrop uses WebAssembly (WASM) — a way to run compiled C/C++ code at near-native speed inside a browser tab. We ship real production tools (ffmpeg, libvips, pdf-lib) compiled to WASM. When you hit Convert, your file never leaves your device — it's processed in memory, in the tab. Full technical explainer →