Trim Video
Choose start and end boundaries for a compatible MP4 or MOV. Fast mode can copy encoded samples between usable keyframes; Precise mode re-encodes nearer the selected boundaries. Review the result because codec and browser support vary.
Stream copy when compatible
Fast mode copies compatible encoded samples between usable keyframes instead of re-encoding them; boundaries and runtime vary by source, browser, and device.
Precise re-encode mode
Precise mode re-encodes near the selected in/out points when browser codec support is available; inspect the exported boundaries.
Scoped local processing
Demux, cut, and remux run on your device for supported inputs. Video contents are not uploaded for processing; site analytics and the assistant are separate.
How to trim a video
- Open the tool and add your video Select a compatible file for Trim Video.
- Review and adjust Drag the timeline handles to choose the start and end of the clip you want to keep, then review the selected boundaries in the preview.
- Export and download Review the exported result from Trim Video, then download it.
Frequently asked questions
Does trimming reduce quality?
For compatible inputs in Fast mode, the tool copies existing encoded samples between usable keyframes instead of re-encoding them. Precise mode re-encodes the selected segment, so output quality can vary with encoder support and settings.
Why does the start time snap slightly?
Fast stream-copy cuts can begin only at available keyframes, so the requested start may be adjusted to a nearby keyframe. Use Precise mode when you need a re-encoded cut closer to the selected frame.
Is there a file size limit?
There is no single reliable browser-wide size limit. Processing uses memory on your device, so the practical limit depends on the file, browser, device memory, selected mode, and clip length.
What video formats can I trim?
Compatible MP4 or MOV inputs may use stream copy. Other supported container and codec combinations require browser decode and encode support and may be re-encoded; availability varies by browser and device.
Can I trim a video on my phone?
On compatible mobile browsers, availability depends on codec support and device memory.
How to verify a Trim Video export
Treat the page preview and the downloaded file as separate evidence. Use a representative clip, keep the untouched source, and record the result that the task actually requires before changing any control.
- Before processing, note the source container, video and audio codecs when known, duration, dimensions, frame rate, orientation, audio-track count, and intended destination. Also record the exact cut, crop, timing, visual correction, or extraction you expect. These observations create a baseline for comparing the export instead of relying on memory.
- Run a short representative sample first and change one setting at a time. Browser codec support, available memory, hardware acceleration, and input structure can affect which processing path is available. A successful preview for one sample shows only that observed case; it does not establish compatibility for every file with the same extension.
- Inspect the preview around the portions most likely to expose defects: the beginning and final frame, cut boundaries, rapid motion, fine text, faces, object edges, gradients, orientation changes, and any section where sound should align with a visible event. For model-assisted tools, look for missed regions, unstable masks, invented detail, or frame-to-frame drift.
- Open the downloaded file in a separate current player rather than reviewing only the in-page preview. Confirm that it starts and ends where expected, plays through without an unexpected stall, and has the intended duration, dimensions, orientation, frame rate, audio presence, and synchronization. Check the file again in the platform or editor that will consume it.
- Compare the exported clip with the untouched source at the same viewing scale and, when useful, matched playback volume. Look for unexpected crops, padding, stretch, softness, banding, halos, color shifts, temporal jumps, repeated or missing frames, and changes in file size or codec that matter to the destination. Decide whether any difference is acceptable for the stated task.
- If the result is missing, fails to play, or differs from the preview, first confirm that the source opens independently. Reload the page, retry with a small controlled sample, reset optional controls, and preserve the exact on-page message. Testing one controlled change at a time makes browser, input, setting, and destination failures distinguishable.
- Record the Trim Video URL, relevant settings, browser and device, date, source identity, output filename, and observed checks. Keep before-and-after files when the result matters. This record supports a reproducible comparison later and avoids treating a changed input, capability, or destination requirement as the same run.