Video Converter

Related: Compress video · MP4 to WebM · Video to GIF · GIF to MP4

Output

Convert video online for delivery-ready MP4 or WebM

Upload clips in common formats (for example MP4, MOV, or MKV), choose MP4 or WebM as the output, then re-encode with controls for quality (CRF), encoder speed (preset), maximum width, and audio—or strip audio for silent video. Conversion runs on the server with FFmpeg: streams are decoded and encoded again, not merely renamed inside a new container.

For animated GIF workflows, use Video to GIF or MP4 to GIF; for efficient silent autoplay from GIF sources, use GIF to MP4. When the priority is shrinking an existing video without switching container, compress video focuses on CRF-based size reduction without the format-choice overhead.

Quick reference

Inputs
MP4, MOV, WebM, AVI, MKV, M4V—typical consumer and screen-capture containers.
MP4 out
H.264 video + AAC audio; broadest playback on phones, editors, and legacy browsers.
WebM out
VP9 video + Opus audio; strong in modern browsers; pair with MP4 when you need a universal fallback.
CRF 23–32 (typical)
Lower keeps more detail (larger files); higher shrinks size with more compression risk.

What the output controls do

These map to the fields in the Output card above:

  • Output format — MP4 (H.264 + AAC) for maximum compatibility; WebM (VP9 + Opus) when your stack accepts it and you want a modern web-first encode.
  • Preset (veryfast → slow) — Slower presets spend more CPU searching for efficiency at the same CRF; veryfast is quickest to finish but may yield slightly larger files.
  • CRF (18–40) — Quality bias for the video stream. Rough bands: ~18–22 for high fidelity archival proxies, ~23–28 for general web, ~29–36 when size dominates and some softness is acceptable.
  • Max width — Downscales frames wider than this value, reducing pixels to encode; leave high when you need full resolution exports.
  • Audio bitrate / Remove audio — Opus (WebM) or AAC (MP4) bitrate when sound matters; check Remove audio for silent loops or picture-in-picture beds.

Tradeoffs and safe use

Lossy codecs discard information you cannot recover from the exported file alone. That is appropriate for final social or web delivery, but risky if the export becomes your only master. Prefer keeping camera originals or high-bitrate mezzanines until the project is locked.

HDR, wide gamut, and log-style sources need careful monitoring after any web encode—tone mapping and gamut assumptions can shift contrast compared with what you saw on a grading monitor.

When not to use this converter

  • Legal or forensic originals — Do not re-encode evidence or contractually locked camera masters without authorization.
  • Complex MKV feature sets — When you need every subtitle track, commentary, or chapter marker intact, use a pro NLE or muxer that preserves those streams intentionally.
  • Already-acceptable uploads — If the platform accepts your current MP4 and size is fine, uploading as-is avoids another generation of loss.

Subtitles, chapters, and multi-track audio

This page optimizes for a single playable video output. Extra audio languages, image-based subtitles, embedded chapters, or vendor-specific HDR metadata may not survive the round trip. If compliance or accessibility depends on those assets, verify the downloaded file in a desktop player before deleting sources.

Video converter questions, answered

Which output format should I choose?

MP4 with H.264 plays almost everywhere: phones, social apps, and older browsers. WebM with VP9 targets modern browsers and can be smaller for some clips. Pick the container your destination accepts.

What video files can I upload?

Common containers such as MP4, MOV, WebM, AVI, MKV, and M4V. The server re-encodes to your chosen output; it does not simply rename the file.

What does CRF mean?

CRF targets quality instead of a fixed bitrate: lower values keep more detail and larger files, higher values shrink the file with more risk of softness or banding in motion and gradients.

Will converting reduce quality?

Re-encoding with a lossy codec (H.264 or VP9 here) can lose detail versus the source, especially across multiple generations. Keep a master when you may edit or re-export later.

How is this different from compress video?

Same FFmpeg pipeline and options. Compress video emphasizes shrinking files; this page emphasizes picking MP4 or WebM when you are changing delivery format.

When should I use MP4 to WebM instead of this page?

Use MP4 to WebM when you only need WebM output. Use this page when you want one upload flow and might switch between MP4 (H.264 + AAC) and WebM (VP9 + Opus) depending on the destination.

Are subtitles, multiple audio tracks, or HDR metadata preserved?

This tool targets a single re-encoded video stream (and one AAC or Opus track unless you remove audio). Image-based subtitles, extra audio languages, chapters, and HDR sidecar metadata may be dropped or flattened. Keep originals when those elements are required for compliance or finishing.