What Is WhatTrainIsItNow.com?

Updated

WhatTrainIsItNow.com is a lightweight dashboard that tracks which Firefox "train" is currently in each release channel. On a single page it shows the current Nightly, Beta, Release, and ESR version numbers, plus the next ship date and merge day. It's useful if you follow Firefox development, need to know what version is about to ship, or want to confirm which channel a given version belongs to. It is a community-style tracker, not an official Mozilla product unless the site itself says otherwise.

What the site tracks

The page is organized around the four Firefox release channels and the milestones that move versions between them.

Item What it tells you
Nightly The current Nightly version number
Beta The current Beta version number
Release The current public Release version
ESR The current Extended Support Release version
Ship date When the next Release is scheduled to ship
Merge day When the next version moves from Nightly to Beta

From the site's own snapshot, the channels read 153 / 115 ESR, 158 Release, 159 Beta, and 160 Nightly, with Firefox 159 shipping on October 27 (in 6 days) and the next merge day on October 22. That single line is the core value: you can see the whole pipeline at a glance.

How to read the numbers

Firefox development runs on a train model. A version starts in Nightly, moves to Beta after a merge day, and then ships as Release. ESR runs on a slower, separate cadence, which is why it shows a much lower number (115 in the snapshot) than the main channels.

A concrete example: if the site shows 160 Nightly and 159 Beta, then version 160 is still under active development, 159 is in beta testing, and 158 is what most users currently have. The "next merge day" date tells you when 160 will move to Beta and 159 will move toward Release.

When it's useful

  • Checking what's about to ship — the ship date answers "when does the next Firefox come out?"
  • Confirming channel versions — useful when a bug report or add-on compatibility note references a specific version.
  • Following the train schedule — merge days and ship dates give you the rhythm of the release cycle.
  • ESR reference — organizations on ESR can confirm the current ESR line.

Limits to keep in mind

The site is a convenience tracker. Dates can shift, and the page reflects what its maintainers have entered, so treat ship dates and merge days as scheduled rather than guaranteed. For authoritative release information, cross-check Mozilla's own release channels. The site does not state pricing or login requirements, so don't assume any particular access model beyond what you see when you visit.

Quick way to use it

  1. Open whattrainisitnow.com.
  2. Read the four channel numbers to see the current Nightly, Beta, Release, and ESR versions.
  3. Check the ship date for the next Release and the merge day for the next channel move.
  4. Use the calendar and "About Firefox Trains" links if you need the fuller schedule or background.

That's the whole workflow — one page, one glance, and you know where Firefox is in its release cycle.