Video & Audio Converter, Trimmer and Compressor
Choose a video or audio file, then pick an output format, quality, and resolution. Enter start and end times to keep only the part you need, or extract just the audio (for example as MP3) from a video. It uses your browser’s built-in video and audio encoders (WebCodecs), so your file is never uploaded. To convert pictures instead, use the Image Format Converter.
🔒 Runs in your browser · Your data is never sent to a server
You can also drag and drop a file here
WAV is uncompressed, so quality has no effect.
Result
How to use
- Choose a video or audio file (drag and drop also works).
- Pick the "Output format" and "Quality". For video, lowering "Resolution (max height)" makes the file smaller.
- To keep only a section, enter times in "Start" and "End" under "Trim (cut out a section)".
- Press "Convert", then save the result with "Download" when it finishes.
Notes
- Speed depends on your device. Long or high-resolution videos can take a while or fail when memory runs out.
- Keep this tab open and in the foreground while converting. Some browsers slow down or pause background tabs.
- Encoding uses your browser’s WebCodecs support, so available input and output formats vary by browser. MP4 (H.264) output works best in Chrome, Edge and Safari, WebM output in Chrome and Edge, and Firefox may have limited encoding support.
- Converting re-encodes the media, so some quality is lost. "High" keeps the loss small but makes a larger file.
- To shrink a file without changing its format, choose the same output format as the original and lower the quality or the maximum resolution.
- The file size limit is 1 GB. The output is built in memory, so large files use a lot of RAM.
- Subtitles, extra audio tracks and chapters are not carried over. Only the main video and audio are written.
- All processing happens in your browser; the file you choose is never sent to a server.
Glossary
Codec
The method used to compress and decompress video or audio data, such as H.264, VP9, AAC or Opus. Two files that are both "MP4" can contain different codecs.
Container (file format)
A wrapper that bundles video, audio and subtitles into one file, such as MP4, WebM, MKV or MOV. Each container supports only certain codecs.
Bitrate
The amount of data per second (bps). A higher bitrate means better quality but a larger file. In this tool, the "Quality" setting decides the bitrate.
WebCodecs
A standard browser API for compressing and decompressing video and audio. This tool uses it to convert files inside your browser.
FAQ
Is my video uploaded to a server?
No. Conversion runs inside your browser using WebCodecs, and the file you choose is never sent anywhere.
How do I make a video file smaller?
Lower the "Quality" or reduce "Resolution (max height)" to 720p or 480p. You can keep the same output format as the original. Re-encoding does cost some visual quality.
Can I extract just the audio from a video?
Choose an audio format such as MP3, M4A, OGG or WAV as the output format, and only the audio is saved. A video with no audio track cannot be converted to an audio format.
Why does conversion fail, or why can’t I use some formats?
Encoding depends on your browser’s WebCodecs support, so supported formats differ by browser. The latest Chrome or Edge is recommended. Conversion can also fail if the source codec cannot be decoded or if a long video runs out of memory.
How do I enter trim times?
Use "90" (seconds), "1:30" (minutes:seconds) or "1:02:03.5" (hours:minutes:seconds.fraction). You can set only the start or only the end; leave both empty to convert the whole file.
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