CF Stopwatch — A Browser Extension to Track Your Solve Times

Revision en1, by pratikrkcha, 2026-02-27 23:41:10

Hey Codeforces!

CF Stopwatch — a tiny browser extension I built that auto-injects a stopwatch directly into Codeforces problem pages. No setup, no manual effort — it just works.


TL;DR

If you want to track how long you actually spend on a problem without leaving the page or starting/stopping a separate timer, CF Stopwatch does that for you automatically.


Why I built it

I kept losing track of how long I was spending on problems. Opening a separate timer, remembering to start/stop it, or finding out it had been running in another tab broke my focus. I wanted a timer that lives inside Codeforces itself and requires zero interaction.


What it does

  • Anti-panic buffer — A 60-second delay before the timer starts so you can read the problem and decide whether to attempt it (or manually start earlier). No clock-stress the moment the page opens.
  • Auto-stop on Accepted — The extension polls the Codeforces API every 5 seconds and freezes the timer as soon as your submission receives Accepted. (You must be logged in for this to work.)
  • Multi-attempt support — Hit Reattempt to reset the clock for a fresh try. Previous AC verdicts are ignored for the new attempt.
  • Smart persistence — The timer only runs while the tab is open. Close the tab and it freezes; reopen and it resumes exactly where it left off. Nothing runs silently in the background.
  • Adaptive theme — The widget reads colours from the Codeforces page at runtime so it blends with light/dark/custom themes automatically.

Screenshots


Installation

Chrome / Chromium

  1. Download and unzip cf-stopwatch-chrome
  2. Go to chrome://extensions, enable Developer mode
  3. Click Load unpacked → select the folder

Firefox

  1. Download and unzip cf-stopwatch-firefox
  2. Go to about:debuggingThis FirefoxLoad Temporary Add-on
  3. Select manifest.json

Download From Here

GitHub: pratikrkcha/CF-Stopwatch


If you find it useful, a star on the repo would mean a lot. Feedback and suggestions welcome — drop them in the comments below!

Pratik Rakhecha


Tags chome extension, mozilla extension, stopwatch, timer

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en1 English pratikrkcha 2026-02-27 23:41:10 2413 Initial revision (published)