Trim Video
Trim a video by start and end time
Configure
About this tool
Choose one supported file from your device (.mp4, .mov, .avi, .mkv, .webm). This workflow does not accept a source URL. Uploaded files are processed by SimplifyConvert's server-side media tools. Temporary working files are scheduled for cleanup after processing, while completed downloads use the site's download-result workflow.
Ready to process
Upload one supported file and start processing.
Keep one continuous section between a start and end time
Trim Video removes the material before the chosen start and after the chosen end. It produces an MP4 containing one continuous interval; it does not join multiple highlights or remove a section from the middle.
Practical trimming tasks
- •Remove setup time from the beginning of a recording.
- •Create a short review excerpt from a longer clip.
- •Discard an unneeded ending before compression or sharing.
How to use this tool
- 1.Upload one MP4, MOV, AVI, MKV, or WebM up to 500 MB.
- 2.Enter start and end times in MM:SS, with the end later than the start.
- 3.Trim and verify the first frame, last frame, duration, audio synchronization, and playback.
Timing and codec behavior
- The engine calculates output duration as end time minus start time and rejects a non-positive range, a start beyond the source, or a requested interval longer than one hour.
- FFmpeg first attempts stream copy, which avoids re-encoding but can begin near a codec keyframe rather than an exact arbitrary frame.
- For certain stream-copy failures, the fallback re-encodes H.264 video at CRF 28 with AAC audio.
Example: keep a demonstration from 00:15 to 01:05
The expected interval is 50 seconds. Play the result from the beginning and near the end: stream-copy seeking can land near available keyframes, so observed boundaries may not be frame-exact for every source.
What a single trim cannot do
- It cannot combine multiple non-contiguous moments into one highlight reel.
- Stream copy depends on source keyframes and container/codec compatibility.
- Damaged files, incompatible streams, invalid times, or demanding files can fail or exceed processing limits.
Fix timing and playback issues
- End rejected: make it later than the start and within the source duration.
- Boundary is slightly early or late: keyframe placement can limit stream-copy precision.
- Need several excerpts: trim them separately and use a video editor to join them.
Continue the workflow
Return to Video tools, or continue with a complementary tool:
Understand duration, bitrate, resolution, and codec tradeoffs
Questions about this specific tool
How is expected duration calculated?
It is the end timestamp minus the start timestamp. For example, 00:15 to 01:05 is 50 seconds.
Is trimming frame-accurate?
Not guaranteed. The primary stream-copy path seeks around codec keyframes, which can affect exact boundaries.
Does the tool re-encode the video?
It first attempts stream copy. A limited fallback path re-encodes H.264 video and AAC audio when certain copy failures occur.
What files can I upload?
The configured inputs are MP4, MOV, AVI, MKV, and WebM, with a 500 MB request limit.