MP4 Compressor

How to Compress MP4 Videos Online

1. Upload Your MP4 File: Drag and drop or click "Add Files" to load MP4 / M4V clips — phone recordings, GoPro / drone footage, screen captures, webinar exports, edited timeline renders. Batch is supported; drop in a whole shoot at once.
2. Pick a Compression Mode: Choose Target file size (%), Specific file size (e.g., 16 MB for WhatsApp, 10 MB for Discord free), Constant Bitrate, Variable Bitrate, Constant Quality (CRF-based), or Constraint Quality. Smart Auto Scale rebalances resolution and bitrate to land at your target without crushing the result.
3. Codec, Resolution, and Trim (Optional): Keep H.264 for maximum compatibility, switch to H.265 / HEVC for roughly 40-50% smaller files at the same quality, or pick AV1 for the smallest possible output on modern devices. Apply a resolution preset (2160p → 1440p → 1080p → 720p → 480p) and use the Trim control to drop unused head / tail before encoding.
4. Compress and Download: Click Compress. Each file processes in your browser session and downloads individually or as a ZIP — no sign-up, no watermark.

Why Compress MP4 Files?

MP4 is the most widely used video container on the open web — phone cameras, screen recorders, editing apps, and streaming exports all default to it. The flip side is size: a 1-minute 1080p H.264 clip at typical phone bitrates lands around 100-200 MB; a 4K clip from a recent iPhone or Android can easily clear 400 MB per minute. Common reasons people compress MP4:

• Messaging apps with hard attachment caps — WhatsApp limits in-chat videos to 16 MB on most accounts (sending as a document raises it to 2 GB, but the video no longer plays inline). Telegram caps free uploads at 2 GB per file and 4 GB on Premium. Signal caps attachments at 100 MB.
• Discord — Free accounts upload up to 10 MB per file (Discord lowered this from 25 MB in 2024). Nitro Basic raises it to 50 MB, full Nitro to 500 MB, and a Boost-Tier-3 server lifts everyone in that server to 100 MB.
• Email — Gmail and Outlook attachments cap at 25 MB and 20 MB respectively before pushing the file to Drive / OneDrive. iCloud Mail caps at 20 MB. A compressed 1-minute 720p clip fits comfortably.
• Faster uploads to YouTube, Vimeo, Drive, and social — Smaller files finish uploading sooner and re-encode faster on the platform side. A 4K source compressed to 1080p H.265 typically uploads 4-6× faster on a typical home connection.
• Storage on phone, laptop, and cloud — iCloud free is 5 GB, Google account free is 15 GB. Long 4K clips eat that quota fast; an H.265 re-encode reclaims 40-60% per file.
• Website embed performance — Compressed video starts playing faster and uses less bandwidth, which matters for hero videos, product demos, and background loops on landing pages.

Compression Mode Quick Guide

CRF Reference — Quality vs Size Tradeoff

x264 / H.264 uses a CRF range of 0-51 with default 23; x265 / H.265 uses the same 0-51 range but a default of 28 that produces equivalent visual quality. Practical "sane" range for both is 18-28.

MP4 vs WebM vs MOV — Container and Codec Choice

Platform Upload Cheat Sheet

Frequently Asked Questions

How much can I reduce an MP4 file?

Typical results: 30-50% with default settings on the same codec (H.264 → H.264 at CRF 23), 50-70% when re-encoding H.264 → H.265 at equivalent quality (CRF 23 → 28), and 80%+ when also downscaling resolution (e.g., 4K → 1080p) or trimming unused footage. A 200 MB phone clip routinely lands at 30-60 MB without visible quality loss. A 4K drone shot at 400 MB / minute can drop to under 100 MB / minute as a 1080p H.265 file.

What's the best codec — H.264, H.265, or AV1?

H.264 for maximum compatibility — every browser, phone, and TV made in the last 15 years plays it. H.265 / HEVC for the best size-to-quality ratio on modern audiences — Safari and Edge play it natively, Chrome added support in version 105 (Sept 2022), and every iPhone since the 6, every modern Android, and every TV made since 2017 has hardware decode. AV1 for the smallest possible files and future-proofing, but encode time is 5-10× longer than H.265 and only devices from 2022+ decode smoothly. For a single deliverable that has to play everywhere with no surprises, H.264 is still the safe pick.

How do I compress an MP4 to fit WhatsApp or Discord?

Pick "Specific file size" and enter 16 MB for WhatsApp in-chat video or 10 MB for Discord free. Smart Auto Scale will rebalance bitrate and resolution to land under the cap. For best results on tight targets, also drop resolution to 720p (or 480p for very short clips on Discord free) and switch the codec to H.265 — you'll get noticeably better quality at the same file size. WhatsApp also accepts videos up to 2 GB if you send them as documents (the recipient downloads instead of inline play).

Will compressing reduce video quality?

It depends on the settings. At CRF 17-22 (H.264) or CRF 22-27 (H.265), most viewers cannot tell the compressed file apart from the source on a normal screen — verified in bit-blind tests. At CRF 23-25 H.264 / 28-30 H.265, quality loss is subtle and only visible on critical content (skin texture, fine grain). At CRF 28+ H.264 you'll see banding and blocking on dark gradients and fast motion. Pick CRF based on viewing target: 17-22 for archival or critical work, 23 for general web, 25-28 for phone-only social uploads.

Can I compress an MP4 without changing resolution?

Yes. Use Constant Quality (CRF), Constant Bitrate, or Variable Bitrate with the resolution left at "Original". The encoder re-evaluates each frame and discards redundancy without rescaling — typical savings of 30-50% on the same codec, more if you also switch to H.265. Resolution downscaling is an additional lever you can apply on top when you need to hit a small cap.

Why does my compressed MP4 look soft / pixelated even at high CRF?

Three usual causes. (1) The source was already heavily compressed — re-encoding a 5 Mbps social-media download at CRF 23 just preserves the existing artifacts; you cannot recover detail that's already gone. (2) Resolution was scaled down too far for the bitrate budget — a 4K source forced into 360p will look soft regardless. (3) The original had heavy film grain or noise; CRF spends bits encoding the noise pattern, so dropping CRF to 20 or applying a light denoise before compression usually fixes it.

Can I batch compress multiple MP4 files at once?

Yes. Drop in a whole folder of recordings or exports and they process in parallel with the same settings, then download individually or as a ZIP. Each file auto-scales independently to hit your target — useful when batch-compressing a mix of 4K and 1080p clips with one "fit under 25 MB" rule.

Does compressing affect audio?

Audio re-encodes by default with sane AAC settings (typically 128 kbps stereo at 48 kHz). For voice-only screen recordings or podcasts inside MP4, you can drop audio bitrate to 64-96 kbps with no noticeable loss and save several MB on long files. Music and ambient audio benefit from keeping 128-192 kbps. Audio bitrate, sample rate, and channel count are exposed in Advanced Options.

What's the difference between MP4, MOV, and WebM?

MP4 is the universal container — every device, every browser, every editor. MOV is Apple's container (Final Cut, iMovie, QuickTime); the codec inside (H.264 or HEVC) is the same as MP4 but the file extension and metadata differ. WebM is the open-web container for VP9 / AV1, plays in Chrome / Firefox but not Safari natively until 14.1+. For sharing and uploading, MP4 wins. See MOV to MP4, MP4 to WebM, and MP4 to MP3 for related conversions. To trim before compressing, use Trim MP4.