SeaMonkey 2.53.9.1

Released September 28, 2021

Warning! The SeaMonkey version available for download from this page is outdated and may suffer from known security vulnerabilities. This page is only available for historic reference.
We strongly advise you to download the current release instead.
  • 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!
  • 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".
  • This release includes official Linux and Windows builds for both x86 and x64 versions.
    If on Linux make sure you download the appropriate installer from the download section. Most recent Linux distributions are provided in x64 (64-bit) versions only. If you choose the wrong version SeaMonkey will likely not start. The x86 (32-bit) version can be used in some x64 distributions only.
    The Windows versions are supported on Windows 7 and higher only. They will not install on an unsupported version. The x64 version will only run on a x64 Windows version. Running the unzipped package on an unsupported version might result in an error displayed or in erratic program behaviour.
    If you use a previous SeaMonkey x86 Windows version please uninstall it before installing the x64 version. Your profile data will be preserved doing this.

Official builds

MD5 sums and SHA1 sums are available for official packages and source tarballs.

Language Version Windows
x64
Windows
x86
macOS
x64
Linux
x64
Linux
x86
Chinese (Simplified) 中文 (简体) 2.53.9.1 Download Download Download Download Download
Chinese (Traditional) 正體中文 (繁體) 2.53.9.1 Download Download Download Download Download
Czech Čeština 2.53.9.1 Download Download Download Download Download
Dutch Nederlands 2.53.9.1 Download Download Download Download Download
English (British) English (British) 2.53.9.1 Download Download Download Download Download
English (US) English (US) 2.53.9.1 Download Download Download Download Download
Finnish suomi 2.53.9.1 Download Download Download Download Download
French Français 2.53.9.1 Download Download Download Download Download
Georgian ქართული 2.53.9.1 Download Download Download Download Download
German Deutsch 2.53.9.1 Download Download Download Download Download
Greek Ελληνικά 2.53.9.1 Download Download Download Download Download
Hungarian Magyar 2.53.9.1 Download Download Download Download Download
Italian Italiano 2.53.9.1 Download Download Download Download Download
Japanese 日本語 2.53.9.1 Download Download Download Download Download
Norwegian (Bokmål) Norsk bokmål 2.53.9.1 Download Download Download Download Download
Polish Polski 2.53.9.1 Download Download Download Download Download
Portuguese (Brazilian) Português (do Brasil) 2.53.9.1 Download Download Download Download Download
Portuguese (Portugal) Português (Europeu) 2.53.9.1 Download Download Download Download Download
Russian Русский 2.53.9.1 Download Download Download Download Download
Slovak slovenčina 2.53.9.1 Download Download Download Download Download
Spanish (Argentina) Español (de Argentina) 2.53.9.1 Download Download Download Download Download
Spanish (Spain) Español (de España) 2.53.9.1 Download Download Download Download Download
Swedish Svenska 2.53.9.1 Download Download Download Download Download

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, 272 MB) - note that it doesn't unpack a subdirectory itself, so create a directory to unpack it in.
  • Source Localisation Tarball (xz, 13 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 2.53.9.1 from the source repository.

Language Packs