Merge video
Join two to six video clips into one MP4 in your browser. Clips are fitted to the first clip’s frame; silent clips get a silent track.
About this tool
Clips that belong together — the parts of a recording, takes from two phones, a screen capture plus its intro — usually end up in a video editor just to be joined. This tool does the join in your browser: pick two to six clips and they are normalized to the first clip’s frame size and frame rate, then concatenated into a single MP4.
Normalization is the honest price of a clean join: clips are re-encoded once (H.264 with AAC audio) so every segment shares identical settings, letterboxed rather than cropped when aspect ratios differ, and clips without an audio track receive a silent one so the soundtrack never breaks mid-file. The join itself copies the normalized segments without further loss.
How to use Merge video
- Choose two to six video clips — they merge in the order listed.
- Run the merge. Each clip is normalized to the first clip’s size, then joined without a second quality loss.
- Preview the merged MP4 and download it.
Keep the original files and inspect the exported result before publishing or sharing it.
Frequently asked questions
My clips have different sizes — what happens?
Every clip is scaled and letterboxed into the first clip’s frame size at 30 fps, so portrait and landscape clips can be joined. Nothing is cropped.
One of my clips has no sound.
It receives a silent audio track during normalization, so the merged file keeps one continuous soundtrack.
Does merging reduce quality?
Clips are re-encoded once during normalization (H.264, CRF 23) so they share identical settings; the join itself is a lossless copy.
Are my files uploaded?
No. FFmpeg runs on your device. The engine assets (about 32 MB) download on first use; your videos stay in browser memory.
What are the limits?
Two to six clips, 150 MiB each and 250 MiB in total. Long or 4K clips can exhaust a phone’s memory — merge shorter clips on mobile.
Related tools
- Video to MP4 — Convert MOV, WebM, MKV and AVI containers to H.264 MP4 locally.
- Extract MP3 from video — Save the first audio track of a video as an MP3 file.
- Video to GIF — Turn a short video segment into a looping GIF with a generated color palette.
- Trim video — Cut a segment from a video in your browser. Fast stream copy first, automatic re-encode fallback for accuracy.
- Screen recorder — Record your screen, a window or a browser tab — with optional microphone — and download the recording. Nothing is uploaded.
- Video watermark remover — Remove a fixed-position watermark or logo from a video you own. Drag a box over the mark and the FFmpeg delogo filter blends it away locally — nothing is uploaded.
- Video Compressor — Shrink MP4, MOV and WebM files for Discord, email and WhatsApp.
- SRT & VTT Subtitle Checker — Find overlaps, bad timestamps, long lines and fast reading speeds.
- Bulk Product Image Resizer — Resize and pad product photos on white or transparent backgrounds.
- Image DPI & Print Checker — Check real PPI, transparency and margins before printing.