The format is the container
MP4, WebM and AVI package video, audio and related data into one file. Renaming the extension does not make the internal tracks more compatible.
Convert video formats online
Will a video not open on the target device or app? Choose MP4, WebM or AVI for where you need to play it, convert one file on your device, then download the result.
Choose a video to convert
Video processed on your device
Video is converted in your browser · The original stays unchanged
Or drop a video here
One MP4, WebM, AVI, MOV or MKV file; decoding depends on its codecConverting... 0%
Output video is ready
How to convert a video format
01
Choose one file from your device
Drop or choose an MP4, WebM, AVI, MOV or MKV file. A supported extension does not guarantee that its internal codec can be read; the tool reports incompatible files.
02
Choose for the playback destination
Use MP4 for broad compatibility, WebM for modern web playback, or AVI when older software specifically requires it.
03
Keep the tab open while processing
Click Convert video. Your device reads the primary tracks and may re-encode them when the source codec does not fit the target format.
04
Test the file before using it
Download the result and check picture, sound, duration and playback at the destination. Keep the source until the new file passes your checks.
Choose MP4, WebM or AVI
| Goal | Choose | Check |
|---|---|---|
| Play on a wide range of devices, browsers or apps | MP4 · H.264 | This is a broadly compatible choice, not a guarantee for every device. Test both picture and sound at the destination. |
| Use the video on a modern website | WebM · prefers VP9, may use VP8 | Test the target browsers and devices because codec support can differ. |
| Older software specifically requires AVI | AVI · MPEG-4 + MP3 | AVI does not automatically mean compatible. Test a short result in the exact target app or device. |
| Need a smaller file, a different frame, a GIF or audio only | Use the tool for that task: Video Compressor, Video Resizer, Video to GIF or Video to MP3 | This page has no target size, bitrate, resizing, trimming or audio-extraction control. |
How are format and codec different?
Codecs encode picture and sound
MP4 output uses H.264; WebM prefers VP9 then VP8 according to device support; AVI uses MPEG-4 Part 2 with MP3. Re-encoding can change detail or file size.
Output and limits to know
One file, three fixed outputs
The tool processes one video at a time and outputs MP4, WebM or AVI. This page has no manual codec, bitrate, resolution or quality controls.
The extension does not confirm the codec
MOV or MKV works only when its internal codecs can be read. Extra tracks, subtitles, chapters and metadata are not guaranteed; inspect the downloaded file.
Conversion is not target-size compression
Re-encoding can reduce quality, and the new file may be smaller or larger than the source. Use Video Compressor when a KB/MB limit is the goal.
Speed depends on the device
Long, high-resolution videos and the AVI path can need more time and memory. Keep the tab open; try a shorter file on a desktop if the browser stops.
If conversion or playback does not work
- Unsupported codec error
- The extension may be valid while the codec inside is unreadable. Try an updated Chrome/Edge browser, another source file or a desktop converter.
- The new file is larger or less clear
- This can happen when fixed settings require re-encoding. Avoid repeated conversions; return to the source and use Video Compressor for a size limit.
- Picture works but audio is missing, or the destination will not open it
- Try MP4 first for broad compatibility and test at the destination. The source codec, extra tracks or limits of the target device may be the cause.
- Progress stops or the tab runs out of memory
- Close other tabs, keep this page in the foreground and try a shorter or lower-resolution video. A desktop tool is often more suitable for large files.
Video is processed on your device
In this conversion workflow, the video is read and the output is created in your browser; the video does not need to be uploaded to an KitoTool server. The result remains in the page session until you download it or leave the page.
Video Compressor
Compress a video by adjusting quality or resolution, then preview and download the result.
Video Resizer
Resize one video by pixels, percentage, device, screen, aspect ratio or social preset, then export one or multiple versions.
Video to GIF
Convert one MP4, WebM, MOV or M4V clip into a looping GIF; choose the clip, width, FPS, colors and dithering, then preview the real result.
Video to MP3
Extract audio from a video and save it as MP3 with 128, 192 or 320 kbps options.
Video Trimmer
Trim one continuous segment from an MP4 or WebM video by start and end time. Preview and download in the source format.
Automatic Video Subtitle Generator
Create subtitles from spoken video in your browser, review and edit each timed cue, then export SRT, VTT, TXT or a captioned video. Codec support depends on the browser.
Online Screen Recorder
Record a screen, app window or browser tab online. Capture supported system audio or microphone, preview and download the WebM video locally.
KitoTool Share — Screen Sharing
Share a screen, chat and meet new friends in public rooms, or create a private room with a code and password. Up to 4 people, no account required.
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