Dropvert

Compress Video

Reduce video file size in your browser. Quality preset, codec, resolution, and audio — all configurable.

Drop files anywhere or click to browse

MP4, MOV, MKV, WebM — up to 200 MB

Reduce video file size in your browser. Pick a quality preset (high / balanced / web-mobile / tiny), choose a codec (H.264 in MP4 or VP9 in WebM), pick a resolution cap, and decide what to do with the audio — Dropvert re-encodes via FFmpeg.wasm and hands you the file. No upload.

How it works

4-step walkthrough

  1. 1

    Drop the video

    MP4, MOV, MKV, WebM, AVI — anything FFmpeg can read. Up to ~200 MB.

  2. 2

    Pick a quality preset

    Four levels span ~30% smaller (near-original quality) to ~80% smaller (aggressive). Each preset maps to a CRF value plus a max-height filter. CRF 22 = visually transparent, CRF 32 = noticeable but acceptable.

  3. 3

    Pick codec, resolution, audio

    H.264 / MP4 is fast and universal; VP9 / WebM produces ~25% smaller files at the same visual quality but encodes ~2× slower. Resolution defaults to "Source" (clamped by the preset) — override to 1080p / 720p / 480p. Audio: re-encode to AAC 128k, passthrough (copy without re-encode), or strip entirely.

  4. 4

    Compress and download

    Re-encoding takes roughly the duration of the source video on H.264, longer on VP9. Output filename ends in .mp4 (H.264) or .webm (VP9).

Why use Dropvert

Local-first, free, no upload required

  • Four quality presets cover most use cases — no need to know what CRF means.
  • Codec choice: H.264 / MP4 (universal playback) or VP9 / WebM (better compression).
  • Explicit resolution cap (Source / 1080p / 720p / 480p) on top of the preset, for when you need a specific dimension.
  • Audio handling: re-encode for compatibility, passthrough for speed + zero quality loss, or strip for the smallest output.
  • Browser-side. Works on private recordings without upload.
  • H.264 output includes the faststart flag so it streams cleanly from a web server (starts playing before fully downloaded).

Frequently asked questions

6 answered

How much can I compress without losing quality?
For most source material: 30–60% size reduction with no visible quality loss on the High preset. Phone-shot footage, screen recordings, and screencasts compress especially well. Heavily-compressed inputs (already-tiny social media clips) compress less because most of the redundancy has already been squeezed out. VP9 typically yields another ~25% smaller files than H.264 at the same perceived quality.
When should I pick VP9 / WebM over H.264 / MP4?
Pick VP9 when output file size matters more than encode speed or older-device compatibility — typically web embeds, hosted gallery uploads, or anywhere you control the playback environment. Stick with H.264 / MP4 when the file will land on phones, in messaging apps, in older video editors, or anywhere universal playback matters. AV1 would compress even better but isn't supported in this tool today (the WASM encoder is too slow to be practical).
Audio passthrough fails — what's going on?
Passthrough only works when the source audio codec is compatible with the output container. MP4 supports AAC, MP3, ALAC, and a handful of others; WebM only supports Opus and Vorbis. If your source uses a codec the chosen container can't hold (e.g. AC-3 audio in an MP4 source going to a WebM output), passthrough fails. Switch to "Re-encode AAC" — adds 5-15s of encode time and produces a guaranteed-playable output.
Will my video lose quality?
Yes — all the presets re-encode to a lower bitrate or smaller resolution. The High preset is visually transparent for most content; Balanced is acceptable for web; Web/Mobile is noticeable but fine for in-feed playback; Tiny prioritizes file size over fidelity. Re-encoding twice (e.g. compressing an already-compressed video again) loses more than re-compressing once.
How long does compression take?
On H.264 + AAC: roughly the duration of the source video. A 5-minute clip takes ~5 minutes on average hardware. VP9 takes ~2× longer at the same preset — the libvpx-vp9 encoder is more compute-heavy. The "veryfast" tier (used in the Tiny preset for H.264, cpu-used=4 for VP9) is ~2× faster than the default but produces slightly larger files. Audio passthrough is essentially free (no re-encode); stripping is even cheaper.
Are my videos uploaded?
No. Compression runs entirely in your browser via FFmpeg.wasm. The video file never leaves your device.

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