📂 Batch Upload Rule
For multi-file uploads, all files in the same batch should use the same source type (for example all JPG or all MP3).
MP4 (MPEG-4 Part 14) is a widely supported video container format. WEBM (WebM) is a web-optimized video format. Explore our Universal Converter to convert other file types.
Quick rules and tips to get the best results.
For multi-file uploads, all files in the same batch should use the same source type (for example all JPG or all MP3).
Set your preferred output quality to balance file size and clarity. Compression behavior is tailored to each file format.
Each conversion request supports up to 200 MB total. Each user can upload a total of 500 MB per hour.
Completed jobs are saved on this device for up to 1 hour, unless you remove them from the list.
Converting MP4 to WEBM re-encodes media with format-specific FFmpeg settings for web and device compatibility. The quality slider maps to VP9 CRF values from 45 down to 24. This workflow keeps controls simple while still allowing quality and file-size tradeoffs on output.
WEBM uses a web-optimized container designed for browser playback. WebM exports run through VP9, AVI exports use MPEG4 qscale, and MP4/MOV/MKV routes use H.264 with AAC audio.
The quality slider maps to VP9 CRF values from 45 down to 24. Lower values prioritize smaller files for upload and messaging, while higher values preserve more motion detail and reduce visible compression artifacts.
This converter keeps controls simple and does not expose manual resize or FPS knobs in the UI. In typical workflows, source resolution and frame cadence are preserved unless encoder constraints require format-specific adjustments.
WEBM output should be tested on your target browser, phone, or editing app. Using mainstream containers and conservative encoder defaults helps reduce playback failures on older devices and social upload pipelines.