Firefox Send
Initial release12 March 2019; 4 years ago (12 March 2019)
Final release
No version number given / 22 May 2021; 2 years ago (22 May 2021)
PlatformWeb browser
TypeSecure file sharing
LicenseMozilla Public License 2.0[1]
Archived 7 July 2020 at the Wayback Machine

Firefox Send was a free and open-source end-to-end encrypted file sharing web service developed by Mozilla.[2] It was operational from August 1, 2017 until July 7, 2020.[3][4]


Firefox Send allowed users to upload computer files, including large files up to 2.5 gigabytes, to the Send website, generating links from which the file could be accessed and downloaded.[5] Users could also set expiration dates or maximum number of downloads for the links.[6]

The service was end-to-end encrypted, meaning only the uploader and those who the links were shared with could view the file.[2]


On August 1, 2017, Mozilla launched Firefox Send via its Test Pilot program. The developers wanted to experiment with end-to-end encrypted data syncing and this service allowed them to try out encrypting large files, gigabytes in size, as opposed to the megabytes usually synced by browsers.[7]

Firefox Send was launched to the public on March 12, 2019.[8] On July 7, 2020, the service was suspended after the discovery that cybercriminals abused it to spread malware and mount spear phishing attacks.[4] Developers attributed these problems to the absence of any form of authentication and the lack of abuse reporting mechanisms. Developers planned to resume service after implementing mandatory authentication via Firefox Account for file uploading and creating malware reporting mechanisms.[4]

On September 17, 2020, as a part of Mozilla's business and products refocusing plans, the service was shut down permanently, along with Firefox Notes.[9][10] The shutdown followed employee lay-offs in August[11] that likely included the staff who would have been responsible for implementing abuse prevention and malware reporting mechanisms.[9]

On July 28, 2023, Thunderbird has announced resurrecting Firefox Send as Thunderbird Send.[12]

See also


  1. ^ deHaan, Peter (2017-07-27). "send/LICENSE at master · mozilla/send". GitHub. Retrieved 2021-03-16.
  2. ^ a b Barrett, Brian (3 December 2019). "Firefox Send Is an Easy Way to Share Large Files Securely". Wired. Archived from the original on 26 February 2020. Retrieved 12 July 2020.
  3. ^ Lardinois, Frederic (2017-08-01). "Mozilla launches experimental voice search, file-sharing and note-taking tools for Firefox". TechCrunch. Retrieved 2023-07-31.
  4. ^ a b c Cimpanu, Catalin (7 July 2020). "Mozilla suspends Firefox Send service while it addresses malware abuse". ZDNet. Archived from the original on 9 July 2020. Retrieved 12 July 2020.
  5. ^ Wallen, Jack (15 January 2020). "What is Firefox Send and How Does it Work". Lifewire. Archived from the original on 13 July 2020. Retrieved 12 July 2020.
  6. ^ Nguyen, Nick (12 March 2019). "Introducing Firefox Send, Providing Free File Transfers while Keeping your Personal Information Private". The Mozilla Blog. Archived from the original on 31 March 2020. Retrieved 12 July 2020.
  7. ^ Lardinois, Frederic (August 1, 2017). "Mozilla launches experimental voice search, file-sharing and note-taking tools for Firefox". TechCrunch. Retrieved 2022-06-16.
  8. ^ Perez, Sarah (12 March 2019). "Mozilla launches its free, encrypted file-sharing service, Firefox Send". Tech Crunch. Archived from the original on 27 March 2020. Retrieved 12 July 2020.
  9. ^ a b Cimpanu, Catalin. "Mozilla shuts down Firefox Send and Firefox Notes services". ZDNet. Retrieved 2020-09-17.
  10. ^ Mozilla. "Update on Firefox Send and Firefox Notes". The Mozilla Blog. Retrieved 2020-09-18.
  11. ^ Brodkin, Jon (2020-08-12). "Mozilla cuts 250 jobs, says Firefox development will be affected". Ars Technica. Retrieved 2020-09-17.
  12. ^ "Thunderbird Is Resurrecting Firefox Send". TilVids. Thunderbird. 2023-07-28. Retrieved 2023-08-23.