The Firefox Send alternative, still zero-knowledge
Mozilla shut down Firefox Send in 2020 — but the need for simple, end-to-end encrypted file sharing didn't go away. SealFile picks up exactly where it left off.
What happened to Firefox Send?
Firefox Send was Mozilla's free, end-to-end encrypted file-sharing service. You'd encrypt a file in your browser, get a link, and set an expiry or download limit. It was loved for being simple and genuinely private.
Mozilla paused it in July 2020 and permanently discontinued it that September after it was repeatedly abused to spread malware. The hosted service is gone for good, and old send.firefox.com links no longer resolve. If you landed here looking for it, you need a replacement.
SealFile vs Firefox Send
| Feature | SealFile | Firefox Send |
|---|---|---|
| Available today | ||
| Actively maintained | ||
| Zero-knowledge (end-to-end) encryption | ||
| Files encrypted in your browser | ||
| Password protection | ||
| Download limits | ||
| Auto-expiry | ||
| No account required | Limited | |
| Open-source encryption |
Firefox Send was a strong, privacy-respecting product — the decisive difference today is simply that SealFile still exists and is maintained.
Why SealFile feels familiar
Same zero-knowledge model
Encrypt in the browser, share a link with the key in the fragment. The server only sees ciphertext.
Optional passwords
Add an Argon2id-derived password for a second layer — even if the link leaks, the files stay locked.
Expiry & download limits
Shares self-delete after your chosen time or download count, just like Send's ephemeral links.
Verifiable, open client
Our encryption code is open source so you can confirm the security claims yourself.
Frequently asked questions
Is Firefox Send still available?
No. Mozilla paused Firefox Send in July 2020 and permanently discontinued it in September 2020. The service and its hosted instance are gone, so existing links no longer work.
Why was Firefox Send shut down?
Mozilla retired Firefox Send after it was increasingly abused to distribute malware and run phishing campaigns. Rather than keep maintaining moderation tooling, Mozilla discontinued the product.
Is SealFile like Firefox Send?
Yes. SealFile uses the same core idea: files are encrypted in your browser with a key that's never sent to the server (it lives in the link fragment). You get optional passwords, expiry, and download limits — and it's actively maintained.
Is SealFile open source?
Our encryption client is open source so you can verify exactly how the cryptography works, the same way you could audit Firefox Send.
Firefox Send and other product names referenced here are trademarks of their respective owners. SealFile is an independent product and is not affiliated with, endorsed by, or sponsored by Firefox Send. This comparison is based on publicly available information as of June 2026 and may change over time — for the most current details, please check Firefox Send's own website.
The encrypted sharing you missed
Encrypt in your browser, share a link, let it expire. No account required.