Which operating system are you using? Windows x64 Windows x86 macOS x64 Linux x64 Linux x86 Would you like to select a different language? Chinese (Simplified) — 中文 (简体) Chinese (Traditional) — 正體中文 (繁體) Czech — Čeština Dutch — Nederlands English (British) English (US) Finnish - suomi French — Français Georgian - ქართული German — Deutsch Hungarian — magyar Italian — Italiano Japanese — 日本語 Norwegian (Bokmål) — Norsk bokmål Polish — Polski Portuguese (Brazilian) — Português (do Brasil) Portuguese (Portugal) — Português (Europeu) Russian — Русский Slovak — slovenčina Spanish (Argentina) — Español (de Argentina) Spanish (Spain) — Español (de España) Swedish — Svenska

Language Version Windows

x64 Windows

x86 macOS

x64 Linux

x64 Linux

x86 Chinese (Simplified) 中文 (简体) 2.53.4 Download Download Download Download Download Chinese (Traditional) 正體中文 (繁體) 2.53.4 Download Download Download Download Download Czech Čeština 2.53.4 Download Download Download Download Download Dutch Nederlands 2.53.4 Download Download Download Download Download English (British) English (British) 2.53.4 Download Download Download Download Download English (US) English (US) 2.53.4 Download Download Download Download Download Finnish suomi 2.53.4 Download Download Download Download Download French Français 2.53.4 Download Download Download Download Download Georgian ქართული 2.53.4 Download Download Download Download Download German Deutsch 2.53.4 Download Download Download Download Download Hungarian Magyar 2.53.4 Download Download Download Download Download Italian Italiano 2.53.4 Download Download Download Download Download Japanese 日本語 2.53.4 Download Download Download Download Download Norwegian (Bokmål) Norsk bokmål 2.53.4 Download Download Download Download Download Polish Polski 2.53.4 Download Download Download Download Download Portuguese (Brazilian) Português (do Brasil) 2.53.4 Download Download Download Download Download Portuguese (Portugal) Português (Europeu) 2.53.4 Download Download Download Download Download Russian Русский 2.53.4 Download Download Download Download Download Slovak slovenčina 2.53.4 Download Download Download Download Download Spanish (Argentina) Español (de Argentina) 2.53.4 Download Download Download Download Download Spanish (Spain) Español (de España) 2.53.4 Download Download Download Download Download Swedish Svenska 2.53.4 Download Download Download Download Download

The SeaMonkey® Project

The SeaMonkey project is a community effort to develop the SeaMonkey Internet Application Suite (see below). Such a software suite was previously made popular by Netscape and Mozilla, and the SeaMonkey project continues to develop and deliver high-quality updates to this concept. Containing an Internet browser, email & newsgroup client with an included web feed reader, HTML editor, IRC chat and web development tools, SeaMonkey is sure to appeal to advanced users, web developers and corporate users.

Under the hood, SeaMonkey uses much of the same Mozilla Firefox source code which powers such products as Thunderbird. Legal backing is provided by the SeaMonkey Association (SeaMonkey e.V.).

SeaMonkey is proudly sponsored by dotcom-monitor, loadview, WebHostingBuddy.com, Web Hosting Professor and Driven Coffee Roasters.

SeaMonkey 2.53.4 released

The SeaMonkey project is proud to present SeaMonkey 2.53.4: The new release of the all-in-one Internet suite is available for download now! 2.53.4 is an incremental update from the 2.53.x branch and incorporates a number of changes, including enhanced Unicode and emoji support, and fixes from the underlying platform code. Before installing it make a full backup of your profile and thoroughly read and follow the Release Notes .

SeaMonkey 2.53.4 is available in 22 languages, for Windows, macOS x64 and Linux.

Automatic upgrades from previous versions are disabled for this release. If you need to upgrade from an earlier version, please download the full installer from the downloads section and install SeaMonkey 2.53.4 manually over the previous version.



For a more complete list of major changes in SeaMonkey 2.53.4, see the What's New in SeaMonkey 2.53.4 section of the Release Notes, which also contain a list of known issues and answers to frequently asked questions. For a more general overview of the SeaMonkey project (and screen shots!), visit www.seamonkey-project.org.

We encourage users to get involved in discussing and reporting problems as well as further improving the product.

SeaMonkey 2.53.4 Beta 1 released

SeaMonkey 2.53.4 Beta 1 is now available for free download on the SeaMonkey website.

2.53.4 will be an incremental update on the 2.53.x branch and incorporates a number of enhancements, changes and fixes to the application as well as those from the underlying platform code. Before installing it make a full backup of your profile and thoroughly read and follow the Release Notes. We encourage testers to get involved in discussing and reporting problems as well as further improving the product.

SeaMonkey 2.53.4 Beta 1 is available in 22 languages, for Windows, macOS x64 and Linux.

SeaMonkey has a new sponsor!

We are now proudly sponsored by:

A big thanks from the SeaMonkey team! And to all our users and readers don't miss the opportunity to check out the fine products or just buy some great coffee for your pleasure.

SeaMonkey and the future

Wow! A new release and two news items together. What is cooking?

With the SeaMonkey 2.49.5 release the 2.49.x line comes to an end. Unless a catastrophic bug is discovered 2.49.5 will be the last ESR 52 based version. Backporting security fixes and at the same time working on the next, already overdue, major release is not possible with the few remaining developers.

Plans are to do further interim 2.53 versions based on a much enhanced Gecko 56 base while working on bringing you the next ESR 60 based 2.57 version. After 2.57 we will decide about the future. The current Mozilla Gecko codebase has seen a flow of constant major changes and api removals in the last 2 years and is no longer really usable for our needs. By the end of the year the SeaMonkey project is expected to be completely independent of Mozilla. We will see how this pans out but we are doing our best and already have a new infrastructure in place where we do builds and website hosting.

We would also like to remind everyone again that this a community project independent of Mozilla. So if you want to continue seeing future SeaMonkey releases please help by either donating money or even better help out with development. We are still committed and hope you are too.

Help squashing bugs in mail and news

Our Thunderbird friends ask for help squashing bugs. If you have some spare time help them and also us because SeaMonkey and Thunderbird use a shared codebase for mail and news.

Some Details from the announcement:

We are grateful to have a very active set of users who generate a lot of bug reports and we are requesting your help in sorting them, an activity called bug triage. We’re holding “Bug Days” on (all day, EU and US timezones) and (EU and US timezones until 4pm EDT). During these bug days we will log on and work as a community to triage as many bugs as possible. With several of us working at the same time we can help each other in real time – answering questions, sharing ideas ideas, and enjoying being with like-minded people.

No coding or special skills are required, and you don’t need to be an expert or long term user of Thunderbird. Some things you’ll be doing if you participate:

Help other users by checking their bug reports to see if you can reproduce the behavior of their reported problem.

Get advice about your own bug report(s).

Learn the basics about Thunderbird troubleshooting and how to contribute.

But we hope you’ll join us on the 8th or the 13th via #tb-qa on Mozilla’s IRC so that we can put these bugs in their place which helps make Thunderbird even better. If you have any questions feel free to email Ryan.

Visit the Thunderbird Blog to see the full announcement.

The SeaMonkey Internet Application Suite

SeaMonkey has inherited the successful all-in-one concept of the original Netscape Communicator and continues that product line based on the modern, cross-platform architecture provided by the Mozilla project.