Video Converter
Turn a video into MP4 or WebM right in your browser. Pick the format, resolution, frame rate and quality, see the estimated file size, then preview and download the converted file. Your video never leaves your device.
- File
- Type
- Size
- Resolution
- Length
- Avg. bitrate
- Aspect
Convert only part of the video
- Output
- —
- Bitrate
- —
- Length
- —
- Takes about
- —
Keep this tab open and visible: browsers slow down hidden tabs, which would drop frames.
What your browser can open and create
Can open (input)
Can create (output)
Checked live in this browser. Chrome and Edge usually create MP4 and WebM, Firefox creates WebM, Safari creates MP4. If a format you need is missing, try another browser.
How to use the Video Converter
- Choose a video by dropping it on the box or clicking to browse. MP4, WebM, MOV and MKV work in most browsers.
- Pick the output format. Only formats your browser can actually create are listed; MP4 (H.264) plays almost everywhere.
- Set resolution, frame rate, quality and audio, and optionally a start and end time. The estimated size updates instantly.
- Press Convert video and keep the tab open and visible. Conversion runs in real time, so a 2-minute clip takes about 2 minutes.
- Preview the result and press Download to save the converted file.
Which video format should you choose?
A video file is a container (MP4, WebM, MKV, MOV) that holds a video codec (H.264, VP9, AV1…) and an audio codec (AAC, Opus…). Compatibility depends mostly on the codecs, not the file extension.
| Output | Best for | Plays on | File size at equal quality |
|---|---|---|---|
| MP4 (H.264 + AAC) | Sharing, phones, editing, social media | Practically everything: iPhone, Android, Windows, Mac, TVs, browsers | Baseline |
| WebM (VP9 + Opus) | Websites, Discord, smaller files | Chrome, Edge, Firefox, Android, VLC; recent Safari | About 20–40% smaller than H.264 |
| WebM (VP8 + Opus) | Fast encoding, older browsers | All modern browsers, VLC | Similar to H.264 |
| WebM (AV1 + Opus) | Smallest files for short clips | Current browsers, VLC 3+, newer phones | Smallest, but slow to encode |
| MKV (H.264) | Archiving, VLC, editing apps | Desktop players; many phones and TVs do not open MKV | Same as MP4 (H.264) |
If you are unsure, choose MP4 (H.264). If your browser does not list it (for example Firefox), WebM VP9 is the best alternative, and the free VLC player opens every format this tool creates.
How this converter works, and its limits
Browsers do not include a general-purpose video converter, so this tool uses the parts they do have: the video is played in a hidden player, each frame is drawn onto a canvas at your chosen resolution, the sound is routed through the Web Audio API, and the browser's MediaRecorder encodes both into the new format. This means:
- Conversion runs in real time. A 10-minute video takes about 10 minutes. Keep the tab visible, because browsers slow down hidden tabs and frames would be dropped.
- Input must be playable in your browser. If the preview does not play, the file cannot be converted here. HEVC (H.265), ProRes, AVI and WMV often fail; open the list "What your browser can open and create" to see what works in your browser.
- Output formats depend on your browser. Chrome and Edge usually create MP4 (H.264) and WebM, Safari creates MP4, Firefox creates WebM.
- One video and one audio track are kept. Subtitles, chapters, extra audio languages and metadata such as GPS location are not copied. Rotation from phone videos is applied, so the result is always upright.
- The frame rate is constant. Choosing 60 fps for a 30 fps source repeats frames; it does not make motion smoother.
- Very large files (several GB) need plenty of free memory, because the converted file is kept in memory until you download it.
Bitrate and file size
The estimated size uses the standard formula size in bytes = (video bitrate + audio bitrate in bits per second) × length in seconds ÷ 8, plus about 2% for the container. The quality presets scale the bitrate with the number of pixels per second: High uses about 0.12 bits per pixel per frame, Balanced 0.07 and Small 0.04. At 1280 × 720 and 30 fps, Balanced is 1280 × 720 × 30 × 0.07 ≈ 1.9 Mbps, or about 15 MB per minute including 128 kbps audio. Match original bitrate reuses the source's average bitrate, scaled down when you lower the resolution.
Frequently asked questions
How do I convert a WebM or MOV video to MP4?
Open the file here, choose MP4 (H.264) as the output format and press Convert video. MP4 output needs a browser whose recorder can encode H.264, such as current Chrome, Edge or Safari. If MP4 is not in the list, your browser can only create WebM.
Why does converting take as long as the video?
The tool plays the video in a hidden player and re-encodes every frame with your browser's built-in MediaRecorder, which works in real time. This keeps everything private and needs no upload or plug-in, but a 5-minute video takes about 5 minutes.
Is my video uploaded to a server?
No. The video is decoded, drawn and encoded inside your browser tab. Nothing is sent over the internet, so it also works with private or confidential recordings.
Which input formats are supported?
Any video your browser can play. MP4 (H.264) and WebM work everywhere; MOV usually works when it contains H.264. HEVC (H.265), ProRes, AVI and WMV only open in some browsers or not at all, and the tool tells you when a file cannot be read.
Can I convert to AVI, MOV or GIF?
No. Browsers can only encode MP4, WebM and in some cases MKV, so those are the formats offered. MP4 (H.264) is the best choice for compatibility with phones, editors and social media.
Will the converted video lose quality?
Every conversion re-encodes the video, so some detail is lost. Use the High quality preset or Match original bitrate to keep it close to the source, and keep the original resolution and frame rate.
Why is my converted file bigger than the original?
If you choose a higher bitrate than the source uses, the file grows without gaining quality. Pick Balanced or Small, or lower the resolution, and check the estimated size before you start.