Merge video and audio online, entirely in your browser.
Remote Merge
Best when you already have separate video and audio direct links.
Local Merge
Best when your files are already on this device and you just want a quick local merge.
Choose video file
Supports MP4, AVI, MOV, MKV, WebM
Choose audio file
Supports MP3, WAV, AAC, M4A, OGG, FLAC
FAQ
Everything you need to know about merging video and audio files in your browser.
What file formats are supported?
Video: MP4, AVI, MOV, MKV, WebM. Audio: MP3, WAV, AAC, M4A, OGG, FLAC. Subtitles: SRT, VTT, ASS, SSA. All common formats are covered.
Is there a file size limit?
We recommend keeping each file under 2 GB for the smoothest experience. Larger files may work depending on your device's available memory.
Is my data private and secure?
Yes. All merging happens entirely in your browser using FFmpeg WebAssembly. Your files are never uploaded to any server, and everything stays on your device.
Do I need to install any software?
No installation is required. Merge Online runs entirely in your browser. We recommend the latest Chrome, Edge, or Firefox with at least 4 GB of RAM.
How fast is the merging process?
Speed depends on your device and file sizes. Most merges finish within seconds because there is no upload queue or server-side rendering step.
Are there any watermarks on the output?
No. The merged output stays clean, with no watermark, no re-encoding artifacts, and no branding added by the service.
Use Cases
Whether you are creating content or organizing files, Merge Online fits your workflow.
Combine separate video and audio tracks from your recording setup for seamless post-production.
Merge interview footage with intro music, background tracks, or sound effects, all locally.
Combine lecture recordings with narration or supplementary audio for polished course materials.
Pair music videos with your final mixed audio tracks without quality loss or re-encoding.
Quickly merge and prepare video content with custom audio before publishing to any platform.