Tails has a time-based release schedule, aligned with Tor Browser release schedule, which itself depends on the Firefox ESR (Extended Support Release) release schedule.

We publish a new version of Tails on each new release of Firefox, usually every 4 weeks.

On top of that, we occasionally publish an extra emergency release in order to quickly fix a critical security vulnerability that became publicly known or is being used in the wild. The most common example of this is when Mozilla publishes a "chemspill" release of Firefox.

See our actual release schedule.


  /          2w       \/   2w    /4d\

previous            freeze        Tor Browser
ESR + Tails         + RC1         ready for QA
release                |                |
  |                    |                |  new ESR
  |                    |                |  + Tails release
  ↓                    ↓                ↓  ↓
0         1         2         3         4

In the above:

  • Tor Browser ready for QA means that binaries for the upcoming Tor Browser are available, ready for testing, but they are not officially out yet: it has to go through Tor's QA process first.

  • ESR + Tails release means Mozilla announces the new Firefox ESR, and we release a new version of Tails (roughly) the same day. This usually happens on Tuesday.

What if things go wrong?

Postponing the final release causes problems for those who have scheduled time for post-release user support, press work, etc..

Also, changing our mind (i.e. releasing a bugfix release instead of a major one) => switching bugfix/major release schedule for the future is probably not an option either.

So we need to have a pessimistic enough RC->final schedule to handle unexpected issues.

Reverting the faulty feature branch is an option too.

Versioning scheme

  • We always increment the first number when switching to a new major release of Debian. When we do this we reset the second number to zero.

  • We also increment the first number whenever it make sense for Tails only (user-visible changes).

  • The second number is incremented for every release that does not increment the first number.

  • We add an extra, third number for emergency releases.

Release candidates and beta releases

Most Tails stable releases are published directly, without a prior beta release or release candidate (RC). But some changes deserve more caution, in which case we often choose to release a beta or RC. See how to decide whether to release a beta or a RC.