Free tennis highlight generator.
Drop in a match video and Slice finds every rally by listening for the sound of ball strikes — then cuts away the dead time between points. The same rally detector that powers match videos in the Slice app, running right here in your browser.
100% private. Your video never leaves this device — we couldn't watch it if we wanted to.
Drop your tennis video here
or browse files — MP4 and MOV straight from your phone work great
Finding your rallies…
Reading the audio track…
Your highlights
Clips are cut losslessly in your browser (no re-encode), so cuts snap to the video's keyframes — expect starts to be off by up to a second. The Slice app cuts frame-exact, crops to 9:16 for sharing, and handles full-length matches.
Filming whole matches? Slice records your match, finds every rally automatically, lets you trim and share the best points — and keeps your scores, stats and rivalries on the record.
Get the app — it's freeHow the tennis highlight maker works.
Drop in your video
Any match or practice footage with sound — a phone on a fence behind the baseline is perfect. The file is read locally; nothing is uploaded.
It listens for ball strikes
A racket hitting a tennis ball makes a sharp crack that rises and dies within a fraction of a second. The detector scans six frequency bands for exactly that fingerprint — and ignores footsteps, chatter, wind and the court next door.
Rallies become clips
Strikes that trade back and forth in tennis rhythm get grouped into rallies, padded with a couple of seconds either side, and handed to you as clips you can play, save, or share.
How to film tennis highlights that cut themselves.
Put the phone behind the baseline, a couple of metres up if you can — a fence post, a tripod, or the pocket of the windscreen mesh all work. From there the camera sees the whole court and, more importantly for this tool, the microphone hears both players' shots clearly.
Keep the original audio. The detector works entirely from sound: if your camera app records without audio, or you've muted the track while editing, there is nothing to detect. Music overlays are fine to add after you've cut the highlights.
Wind is the enemy. A steady rumble is handled — the algorithm normalises to each recording's own noise floor, and it survives rain on a metal roof — but strong gusts directly on the mic can bury the ball strike itself.
Most amateur tennis videos are 90% walking, ball collection, and towel breaks. In a typical one-hour recording, actual play adds up to well under fifteen minutes — which is why nobody rewatches raw match footage, and why coaches ask for clips instead of full videos.
This tool exists because cutting that footage by hand is miserable. Scrubbing an hour of video for twenty rallies takes most of an evening; the detector does it in seconds, on your device, and it keeps the point and the reaction after it — the part you actually want to share.
It's the same v4 rally-detection algorithm that ships in the Slice app, where it runs on full-length match videos, cuts frame-exact clips, and posts your best points next to the score your opponent confirmed.
Tennis highlight questions, answered.
Is my tennis video uploaded to a server?
No. The whole analysis runs inside your browser using Web Audio — the video never leaves your device, nothing is stored, and there's no account or sign-up. You can watch the network tab while it works: nothing goes out.
How does it detect the rallies?
From sound alone. Ball strikes are sharp, fast-decaying transients that stand out against the recording's own noise floor. The detector measures that contrast in six frequency bands, keeps only strikes that are loud for your recording, checks the back-and-forth rhythm is plausible tennis, and groups them into points.
Which video formats work?
Anything your browser can decode: MP4 and MOV straight off a phone are ideal, WebM works, and an audio-only file (M4A, WAV, MP3) works too if you just want the timestamps.
How long can the video be?
The browser holds the decoded audio in memory, so up to roughly 30–45 minutes is comfortable (hard limit: one hour or 2 GB) on most machines. For full matches, the Slice app runs the same detector natively on your phone — a one-hour match analyses in about a minute, with no length limit.
Why did it miss a rally, or clip something that isn't one?
It has to be able to hear the ball. Distant filming, muted or replaced audio, or a serve drowned by a gust will be missed; a neighbour's court very close to the mic can occasionally sneak in. Filming from behind the baseline with original audio fixes almost all of it.
Is it really free? What's the catch?
Free, no watermark, no sign-up, and your footage stays yours. We built it because it shows off what the Slice app does with match videos — if you like this, you'll like the app; that's the whole business model.
Highlight generators for every racket sport.
Now imagine this for
your whole tennis life.
Match videos with every rally found automatically. Scores your opponent confirms. Rivalries, stats and a record that means something — for tennis, padel, pickleball, badminton and ping pong.