How small can I go without visible loss?

For 1080p, 4–6 Mbit/s (about 30–45 MB per minute) is transparent on phones and laptops; 720p at 2–3 Mbit/s is fine for messaging. Below that, fast motion starts to block.

What are the common size limits?

Gmail 25 MB, Outlook 20 MB, WhatsApp 16 MB (64 MB on some versions), Discord 8 MB free / 50 MB Nitro, iMessage about 100 MB.

Does it keep the audio?

Yes, audio is re-encoded to AAC at 128 kbps, which is inaudibly different from the source for speech and music.

Is the video uploaded?

No. Compression runs entirely in your browser; a 4 GB file never leaves your device.

Video Converters

Compress MP4

A phone MP4 is recorded at a bitrate meant for editing, not sharing. Re-encode it at a sensible bitrate — or straight to a target size — and it looks the same at a quarter of the size.

Runs in your browser — files never leave your device.

Drop MP4 file here

or click to browse · paste from clipboard · up to 4000 MB

Select file

Options

Compress by

Target size (MB)

Quality

Resolution

Frame rate

About Compress MP4

MP4 size is almost entirely bitrate. Phones and screen recorders use 20–100 Mbit/s so that footage survives editing; playback on a phone screen needs 3–8 Mbit/s. Re-encoding at a bitrate matched to the resolution halves or quarters the file with no visible difference.

Encoding uses your browser’s hardware-accelerated H.264 encoder through WebCodecs, so a 5-minute 1080p clip finishes in about the time it takes to play. If the result would be larger than the original, you get the original back unchanged.

How to compress MP4

Drop the MP4 onto the page.
Choose “Target file size” and type the limit (25 MB for Gmail, 16 MB for WhatsApp, 8 MB for Discord), or pick a quality preset.
Optionally lower the resolution to 720p; click Compress and download.

About the format

MP4 · MPEG-4 Part 14 video · .mp4

The video format that works everywhere: phones, TVs, browsers, social networks. Normally H.264 video with AAC audio.

MP4 is a container; the codec inside (H.264, HEVC/H.265, AV1) decides what can play it.
H.264 MP4 is the safe choice for uploads and sharing; HEVC MP4 from newer iPhones needs extra codecs on Windows.
The “moov atom” placement decides whether a browser can start playing before the whole file downloads.

Related conversions

Compress VideoPopularMake a video small enough for email, WhatsApp or uploads.MOV to MP4PopulariPhone/Mac MOV to MP4, usually without re-encoding.MP4 to GIFPopularOn-deviceVideo clip to an animated GIF with trim and size controls.MP4 to WebMOn-deviceMP4 to smaller WebM (VP9/Opus) for websites.Video ConverterAny video format to any other, with codec options.MKV to MP4PopularMKV to MP4 by remuxing, lossless and fast.

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