---
title: "Compress MP4 Video Online — Free & Private | Compress Pro"
description: "Shrink MP4 videos right in your browser — set a quality or a target size like 10 MB for Discord. Nothing is uploaded, no watermark. Free & private."
canonical: https://compress-pro.com/compress-mp4
---

# Compress MP4 videos.

> Shrink MP4s on your device — under any upload size limit.

Compress MP4 files right on your own device — **no upload, no queue, no watermark**. Set a quality for a smaller look-alike, or type the limit you’re fighting and target-size mode finds the settings that fit. Audio is carried over untouched whenever possible.

**No uploads · No ads · Free & open source.**

## How it works

1. Drop files anywhere on the page, click to browse, or paste with Ctrl/⌘ + V.
2. Pick a quality or preset — or set an exact target size and let the tool find it.
3. Compress, compare before/after, and download — individually or as a ZIP.

## Quality mode vs target-size mode

Quality mode is for “make it smaller, keep it looking good” — the tool picks settings matched to resolution and frame rate. Target-size mode is for hard limits: it works backwards from your number and the clip duration, so a 90-second clip and a 9-minute clip both land under the same cap — the long one just looks softer.

## Recommended targets by destination

| Destination | Setting |
| --- | --- |
| Discord (free tier) | Target size: 10 MB |
| Email attachment | Target size: 19 MB |
| Website or CMS upload | Quality 70, max dimension 1920 px |
| Compatible master copy | Quality 90, original size |

## Why MP4 is the safe output

MP4 (H.264) plays on effectively everything made this decade — Windows, Android, TVs, editors, browsers, upload forms. If your source is a newer iPhone recording (HEVC), converting costs some efficiency but buys universal playback; keep the quality higher to compensate. For the smallest file where compatibility doesn’t matter, the [Compress video](https://compress-pro.com/compress-video) tab’s WebM output beats it.

## Under the hood

Compression runs on WebCodecs — the H.264 encoder built into your browser, usually the same hardware block that records your screen — while mediabunny does the container work of reading the source MP4 and writing the new one around the fresh video track. The quality slider maps to a bitrate matched to the clip’s resolution and frame rate, capped so the re-encode never spends more bits than the original. Everything happens on your device, which is why there is no upload, no queue and no watermark.

## Frequently asked questions

### How much smaller will my MP4 get?

Phone and screen recordings typically shrink 50–80% at the default quality, because they were encoded generously at capture time. Videos that were already compressed hard shrink less — the tool keeps the original if it can’t beat it.

### How do I fit Discord or email limits?

Switch to target-size mode and type the cap itself — 10 MB for Discord’s free tier, 19 MB to send reliably by email. The tool aims the file at your number and lands just under it.

### Will it lose quality?

MP4 is lossy, so re-encoding trades some detail for size — at the default quality the difference is hard to spot on phone footage. HDR sources are tone-mapped to standard colors; the tool warns you when that applies.

### Is my video uploaded?

No. Encoding runs on your own hardware from first frame to last — nothing streams to a server, which is also why there is no file-size cap and no queue. Close the tab and every trace of the footage is gone. Want proof? Run one file through, switch your connection off, and run another — it still works.

## Related tools

- [Compress videos](https://compress-pro.com/compress-video)
- [Convert MOV to MP4](https://compress-pro.com/mov-to-mp4)
- [Convert MP4 to WebM](https://compress-pro.com/mp4-to-webm)
- [Convert MP4 to GIF](https://compress-pro.com/mp4-to-gif)

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Part of [Compress Pro](https://compress-pro.com/) — every tool page has a markdown twin at `<page url>.md`. Full tool index: [llms.txt](https://compress-pro.com/llms.txt)