Stopwatch — Laps & Split Times
Start, lap, and stop a high-resolution stopwatch with lap table export for workouts or QA tests.
How it works
- 1Configure your options above
- 2Click "Generate" — processing happens in your browser
- 3Copy or download the result
What to do next
About Stopwatch
Stopwatch is the kind of utility you bookmark and reach for when you need it. Start, lap, and stop a high-resolution stopwatch with lap table export for workouts or QA tests. It loads quickly, works on any modern browser, and produces a result you can download or copy in a single click.
Stopwatch runs on standard browser APIs — an open-source, well-audited engine that performs the web and productivity utility natively in the browser. It accepts the formats listed in the upload area and produces output that opens in any standard web utility viewer. Per-run input is capped at 0 MB.
Most people land on Stopwatch via a search at the moment they actually need the tool. That shapes the design: the page is a single screen with the input on one side, the controls in the middle, and the result on the other, so a first-time visitor can complete the job without reading documentation.
The browser sandbox isolates the page's JavaScript from the rest of the system, the same way it isolates every other tab you have open. Stopwatch works inside that sandbox: it reads the file you give it, processes it with standard browser APIs, and writes the result back. Nothing leaves the page's memory unless you choose to download or copy it.
The hard constraints are easy to remember. Maximum input: 0 MB. Multiple files per run: no — one input at a time, by design, to keep results predictable. The same controls apply on every run.
As a workflow component, Stopwatch is the part you reach for when a single, well-defined web and productivity utility step needs to happen. It performs that step and returns a standard file you can carry into the next part of your pipeline.
Stopwatch fits naturally into the workflow of creators experimenting with formats and teachers building resource lists, both of whom typically need a fast result inside the browser. There is no learning curve to budget for: anyone who has used a typical web upload form can complete a run on the first try.
Once the engine finishes, the output is offered as an immediate download. There is no preview gate, no email-wall, and no "register to download" intermediary — the file is yours the moment it is ready.
The transformation in Stopwatch is deterministic — the same input plus the same options produces the same result every run. That predictability matters when the result has to match an upstream specification or be reproducible later.
Stopwatch is structured around the idea that a useful tool should be its own page. Open the page, do the work, close the tab — the page is the entire product. There is no onboarding flow because there is nothing to onboard into.
If you want to get the most out of Stopwatch, three small habits help. Drag-and-drop is faster than the file picker once you get used to it. The keyboard shortcut for downloading the result is whatever your browser uses for "save link as," because the result is a normal download. And if you are working on a sensitive file, processing in an Incognito or Private window is a good extra layer — it leaves no trace in browser history when the tab closes.
Stopwatch fits the gap where opening a desktop app feels heavy and writing a script feels overkill. The page handles the common web and productivity utility task with sensible defaults so a single visit usually completes the job; for highly specialised work, a dedicated desktop application can offer more knobs to turn.
If the result is not what you expected, the most common causes are easy to check. Confirm the input is under the 0 MB ceiling — files just above the cap fail silently because the engine refuses to allocate the buffer. Confirm the input is one of the supported formats. And if the page itself feels slow, try closing other heavy tabs to free up memory; the engine runs in your browser, so it competes for the same resources as everything else open.
That is the whole tool. Use Stopwatch for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.
How it works
- 1Open Stopwatch in your browser. The page loads quickly and the tool is ready to use the moment it becomes interactive.
- 2Select the web utility file you want to process — drag-and-drop and the file picker both work.
- 3Adjust the options to match what you need. Sensible defaults cover the most common case, so you can usually skip this step.
- 4Click to start the job. The engine (standard browser APIs) processes the input in the page; you can watch the progress indicator until it completes.
- 5Download the result. The file is generated in your browser and saved through your normal download flow.
- 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.
Common use cases
- Plan content without paying for a SaaS dashboard using Stopwatch.
- Generate a campaign asset in seconds for a quick test.
- Run a fast accessibility check before publishing.
- Preview how a result looks before deploying it.
- Pull a quick reference number for a status update.
- Validate a setting before circulating it to a team.
- Sanity-check a webhook response while debugging.
- Compare two product variations side by side.
- Audit a marketing page before launch.
- Run a one-off check during a meeting without context-switching.
FAQ
How accurate is the stopwatch?
Display uses requestAnimationFrame or high-resolution timers; OS scheduling still adds tiny jitter.
Can I copy lap data?
Yes — export laps as CSV or plain text to paste into spreadsheets or test reports.
Does clearing laps reset the main clock?
No — lap clears only the table; use reset to zero the main elapsed timer.
Will it run while minimized?
Elapsed time continues, but background throttling may affect ultra-precise lap timestamps.
Are lap times private?
Yes — laps remain in page memory until you refresh; nothing is uploaded for analysis.
Which browsers are supported?
Works in Chrome, Firefox, Safari, and Edge; performance.now improves precision where available.
Does Stopwatch work on a phone or tablet?
Stopwatch runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 0 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.
Will Stopwatch ask me to pay to download the result?
Stopwatch is free to use. The processing runs in your browser, which keeps the per-user cost low enough that the tool can be offered openly. The download is the same file the engine produced — you can use it for as many runs as you need.
Does Stopwatch reduce quality of the result?
Stopwatch is built to preserve quality wherever the underlying web utility format allows it. Operations that are mathematically lossless (e.g. structural transformations, lossless re-encoding) round-trip with no perceptible change. Operations that involve a lossy codec inevitably introduce small artefacts at the byte level, but the defaults aim at the sweet spot where output looks or sounds the same to a normal viewer or listener while still being meaningfully smaller or faster than the input.
Does Stopwatch work with screen readers?
Stopwatch uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
Are there any restrictions on using Stopwatch at work?
Stopwatch can be used for personal and commercial work alike — there is no separate "business" licence to purchase. The output you generate is yours to use however you want, including in client deliverables, internal documents, or commercial products. Favtoo's only ask is fair, individual use; the tool is not designed to be embedded as a backend service or wrapped behind an API for resale.
How fast is Stopwatch?
Most jobs finish in seconds. Speed scales with input size and with how many CPU cycles your browser tab has available — the engine runs in your browser, so it shares resources with whatever else you have open. For inputs near the 0 MB ceiling, expect anywhere from a few seconds to roughly a minute on a typical laptop. Closing other heavy tabs noticeably speeds things up.
How is Stopwatch different from desktop apps that do the same thing?
Desktop apps usually have more advanced features but require installation, maintenance and (often) a licence. Paid online tools are convenient but route your file through their servers and gate downloads behind accounts. Stopwatch sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common web and productivity utility operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
Can I process multiple files at once with Stopwatch?
Stopwatch processes one input at a time by design — it keeps memory usage predictable on lower-end devices and makes results easier to verify. To handle a folder, run the tool once per file; the page stays loaded between runs and remembers your last-used settings, so the second run is essentially instant.
Why is my browser prompting me when I open Stopwatch?
Stopwatch only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.