SeaMonkey Download & Releases
Main Downloads
SeaMonkey 2.53.21SeaMonkey 2.53.21
Released June 5, 2025
- Release Notes - The release notes describe new changes, system requirements, installation instructions, and known issues in this release - please read them carefully before using this version of SeaMonkey!
- This version of SeaMonkey makes changes to your profile that can't be reverted in the case where you want to go back to a version earlier than 2.53.1. You MUST absolutely do a full backup of your profile before using this application.
- If you are using NoScript you might encounter a certificate error when trying
to download SeaMonkey from this site. NoScript tries to force an https
connection for an http only site. It is not a NoScript problem but how the
Mozilla server, from which downloads are delivered, is configured.
In this case please add download.cdn.mozilla.net to the NoScript "Never force secure (HTTPS) connections" options or turn off NoScript for this download only. The settings are located in the NoScript options under "Advanced->HTTPS".
Official builds
MD5 sums and SHA1 sums are available for official packages and source tarballs.
Source code
The source code is available either as a tar package or from the comm source repository, mozilla source repository and l10n source repository on GitLab.
- Source Code Tarball (xz, 237 MB) - note that it doesn't unpack a subdirectory itself, so create a directory to unpack it in.
- Source Localisation Tarball (xz, 14 MB) - note that it doesn't unpack a subdirectory itself, so create a directory to unpack it in.
- The README file explains how to pull SeaMonkey 2.53.21 from the source repository.
Language Packs
See the activation notes for how to install those packages.
Chinese (Simplified), Chinese (Traditional), Czech, Dutch, English (British), English (US), Finnish, French, Georgian, German, Greek, Hungarian, Italian, Japanese, Norwegian (Bokmål), Polish, Portuguese (Brazilian), Portuguese (Portugal), Russian, Slovak, Spanish (Argentina), Spanish (Spain), Swedish,
SeaMonkey 2.53.21 Beta 1
Released May 1, 2025
- Release Notes - The release notes describe new changes, system requirements, installation instructions, and known issues in this release - please read them carefully before using this version of SeaMonkey!
- This preview of SeaMonkey's future is available from the SeaMonkey 2.53.21 Beta 1 download page.
Old and Unofficial Releases
The SeaMonkey Project only supports the latest stable version of SeaMonkey.
The below versions are only listed for historical reasons.
For some legacy platforms like PPC Mac, the SeaMonkey Project has dropped
support. There are however independent projects that continue to support
some of these platforms. To learn more, see Latest Releases
for Legacy Platforms.
Previously released versions of SeaMonkey:
- 2.53.21 Beta 1
- 2.53.20
- 2.53.20 Beta 1
- 2.53.19
- 2.53.19 Beta 1
- 2.53.18.2
- 2.53.18.1
- 2.53.18
- 2.53.18 Beta 1
- 2.53.17.1
- 2.53.17
- 2.53.17 Beta 1
- 2.53.16
- 2.53.16 Beta 1
- 2.53.15
- 2.53.15 Beta 1
- 2.53.14
- 2.53.14 Beta 1
- 2.53.13
- 2.53.13 Beta 1
- 2.53.12
- 2.53.12 Beta 1
- 2.53.11.1
- 2.53.11
- 2.53.11 Beta 1
- 2.53.10.2
- 2.53.10.1
- 2.53.10
- 2.53.10 Beta 1
- 2.53.9.1
- 2.53.9
- 2.53.9 Beta 1
- 2.53.8.1
- 2.53.8
- 2.53.8 Beta 1
- 2.53.7.1
- 2.53.7
- 2.53.7 Beta 1
- 2.53.6
- 2.53.6 Beta 1
- 2.53.5.1
- 2.53.5
- 2.53.5 Beta 1
- 2.53.4
- 2.53.4 Beta 1
- 2.53.3
- 2.53.3 Beta 1
- 2.53.2
- 2.53.2 Beta 1
- 2.53.1
- 2.53.1 Beta 1
- 2.49.5
- 2.49.4
- 2.49.3
- 2.49.2
- 2.49.1
- 2.48
- 2.48 Beta 1
- 2.46
- 2.40
- 2.39
- 2.39 Beta 1
- 2.38
- 2.38 Beta 1
- 2.35
- 2.33.1
- 2.33
- 2.33 Beta 1
- 2.32.1
- 2.32
- 2.32 Beta 3
- 2.32 Beta 2
- 2.32 Beta 1
- 2.31
- 2.31 Beta 2
- 2.31 Beta 1
- 2.30
- 2.30 Beta 2
- 2.30 Beta 1
- 2.29.1
- 2.29
- 2.29 Beta 2
- 2.29 Beta 1
- 2.26.1
- 2.26
- 2.26 Beta 2
- 2.26 Beta 1
- 2.25
- 2.25 Beta 3
- 2.25 Beta 2
- 2.25 Beta 1
- 2.24
- 2.24 Beta 1
- 2.23
- 2.23 Beta 2
- 2.23 Beta 1
- 2.22.1
- 2.22
- 2.22 Beta 2
- 2.22 Beta 1
- 2.21
- 2.21 Beta 2
- 2.21 Beta 1
- 2.20
- 2.20 Beta 3
- 2.20 Beta 2
- 2.20 Beta 1
- 2.19
- 2.19 Beta 2
- 2.19 Beta 1
- 2.18 Beta 4
- 2.18 Beta 3
- 2.18 Beta 2
- 2.17.1
- 2.18 Beta 1
- 2.17
- 2.17 Beta 4
- 2.17 Beta 3
- 2.17 Beta 2
- 2.16.2
- 2.16.1
- 2.17 Beta 1
- 2.16
- 2.16 Beta 5
- 2.16 Beta 4
- 2.15.2
- 2.16 Beta 3
- 2.16 Beta 2
- 2.15.1
- 2.16 Beta 1
- 2.15
- 2.15 Beta 6
- 2.15 Beta 5
- 2.15 Beta 4
- 2.15 Beta 3
- 2.15 Beta 2
- 2.14.1
- 2.15 Beta 1
- 2.14
- 2.14 Beta 5
- 2.14 Beta 4
- 2.14 Beta 3
- 2.13.2
- 2.14 Beta 2
- 2.14 Beta 1
- 2.13.1
- 2.13
- 2.13 Beta 6
- 2.13 Beta 5
- 2.13 Beta 4
- 2.13 Beta 3
- 2.12.1
- 2.13 Beta 2
- 2.13 Beta 1
- 2.12
- 2.12 Beta 6
- 2.12 Beta 5
- 2.12 Beta 4
- 2.12 Beta 3
- 2.12 Beta 2
- 2.12 Beta 1
- 2.11
- 2.11 Beta 6
- 2.11 Beta 5
- 2.11 Beta 4
- 2.11 Beta 3
- 2.10.1
- 2.11 Beta 2
- 2.11 Beta 1
- 2.10
- 2.10 Beta 3
- 2.10 Beta 2
- 2.10 Beta 1
- 2.9.1
- 2.9
- 2.9 Beta 4
- 2.9 Beta 3
- 2.9 Beta 2
- 2.9 Beta 1
- 2.8
- 2.8 Beta 6
- 2.8 Beta 5
- 2.8 Beta 4
- 2.8 Beta 3
- 2.7.2
- 2.7.1
- 2.8 Beta 2
- 2.8 Beta 1
- 2.7
- 2.7 Beta 5
- 2.7 Beta 4
- 2.7 Beta 3
- 2.7 Beta 2
- 2.7 Beta 1
- 2.6.1
- 2.6
- 2.6 Beta 4
- 2.6 Beta 3
- 2.6 Beta 2
- 2.6 Beta 1
- 2.5
- 2.5 Beta 4
- 2.5 Beta 3
- 2.5 Beta 2
- 2.5 Beta 1
- 2.4.1
- 2.4
- 2.4 Beta 3
- 2.4 Beta 2
- 2.4 Beta 1
- 2.3.3
- 2.3.2
- 2.3.1
- 2.3
- 2.3 Beta 3
- 2.3 Beta 2
- 2.3 Beta 1
- 2.2
- 2.2 Beta 3
- 2.2 Beta 2
- 2.2 Beta 1
- 2.1
- 2.1 RC 2
- 2.1 RC 1
- 2.1 Beta 3
- 2.1 Beta 2
- 2.1 Beta 1
- 2.1 Alpha 3
- 2.1 Alpha 2
- 2.1 Alpha 1
- 2.0.14
- 2.0.13
- 2.0.12
- 2.0.11
- 2.0.10
- 2.0.9
- 2.0.8
- 2.0.7
- 2.0.6
- 2.0.5
- 2.0.4
- 2.0.3
- 2.0.2
- 2.0.1
- 2.0
- 2.0 RC 2
- 2.0 RC 1
- 2.0 Beta 2
- 2.0 Beta 1
- 2.0 Alpha 3
- 2.0 Alpha 2
- 2.0 Alpha 1
- 1.1.19
- 1.1.18
- 1.1.17
- 1.1.16
- 1.1.15
- 1.1.14
- 1.1.13
- 1.1.12
- 1.1.11
- 1.1.10
- 1.1.9
- 1.1.8
- 1.1.7
- 1.1.6
- 1.1.5
- 1.1.4
- 1.1.3
- 1.1.2
- 1.1.1
- 1.1
- 1.1 Beta
- 1.1 Alpha
- 1.0.9
- 1.0.8
- 1.0.7
- 1.0.6
- 1.0.5
- 1.0.4
- 1.0.3
- 1.0.2
- 1.0.1
- 1.0
- 1.0 Beta
- 1.0 Alpha