A browser chronometer for race organisers — nothing to install, no account. Record finishers, see live rankings and pace, then export to CSV. It works offline and your results stay on your device.
No app store, no sign-up — it runs right in your browser.
Crono suits smaller races where runners finish a few at a time. The organiser sets the start; volunteers then tap in each bib number as runners arrive — at the finish line or any point on the course.
No signal at the start, finish or a checkpoint? Crono works fully offline — every time is saved on the device.
Before race day, you can generate and print your own bib numbers — free. Generate bib numbers
Type a bib number and tap Record as each runner finishes. Quick and accurate.
See live results by overall, men, women and age group — switch with one tap.
Add the distance and see each runner's pace per kilometre.
Import your start list (CSV) to show names and group runners automatically.
Download all results as a spreadsheet — ready to publish or share.
Open it once online, then time the whole race with no signal. Nothing is uploaded.
Open a big leaderboard in a second tab for a monitor or projector — it updates live as you record, fully offline.
Optional: POST results as JSON to your own webhook — feed a scoreboard, website or app, kept in sync every few seconds.
Organising the event? Generate a range of numbered bibs with your event name, date and logo — pick a colour theme and download a clean, print-ready PDF (2 per A4 page). No timing needed; do it days before the race.
Generate bib numbersYou don't have to install anything — Crono runs in any browser straight from the web. But if you'd like a one-tap, full-screen launcher that also works offline, you can optionally install it as an app (it's a PWA), on mobile and desktop. No app store, no account.
Open Crono in Safari, tap the Share button (the square with an up-arrow), choose Add to Home Screen, then Add.
Open Crono in Chrome, tap the ⋮ menu, choose Install app (or Add to Home screen), then Install.
In Chrome or Edge, click the install icon in the address bar (or menu → Install Crono). It opens in its own window.
Tip: open Crono online once first so it can install and cache itself — after that it works with no connection.
Yes — it’s completely free and open-source. No account, no paywall.
Yes. Open Crono once while you have a connection (so it can load and install), then it keeps working completely offline — recording finishes, rankings, pace and exports all work with no signal. Great for start/finish lines with poor reception.
Yes — Crono installs on mobile too. On iPhone/iPad use Safari's Share → Add to Home Screen; on Android use Chrome's ⋮ menu → Install app; on desktop click the install icon in the address bar. Once installed it launches full-screen and runs offline.
No — your start time, results and participants are saved on your device and stay there when you go offline, refresh or reopen the app. They're not sent anywhere. For extra safety (or to move to another device), use Backup to download a file you can Restore later. Clearing your browser's site data is the only thing that wipes them.
Times are recorded to the centisecond using your device clock. It’s great for club and in-house races, but for official, certified events keep a backup timing method.
Import a participant CSV with number, name, sex, birth_year. Crono derives standard 10-year athletics categories and lets you rank by them. You can also fill missing data inline.
Yes — one click downloads a CSV with place, category place, name, sex, category, time and pace.
Only in your browser (localStorage). Nothing is sent to a server; the operator can’t see or recover it, so export anything important.
Open it in your browser and start the clock — no setup.
Launch the timer