Compresser Vidéo Gratuit En Ligne - Réduire Taille MP4, MOV

Compressez rapidement des vidéos en ligne gratuitement. Réduisez la taille des fichiers MP4, MOV et 4K sans perte de qualité. Compression instantanée, sans inscription.

ou déposez les vidéos ici

Max 2 Go par fichier · Moins de 500 Mo recommandé pour une meilleure vitesse

⚡ All compression happens in your browser using FFmpeg.wasm — your videos never leave your device. First compression may take a moment to load the engine. Supported: MP4, WEBM, AVI, MKV, MOV.

Compress video down to a sendable size

Lower bitrate and resolution with a live size estimate, so you can trade quality for size deliberately.

Fit WhatsApp, email and portal limits

A 25 MB email cap or a 16 MB message limit usually needs a bitrate drop, not a shorter clip. Compress and keep the whole video.

Try this tool

Bitrate is what controls the size

Halving bitrate roughly halves the file. Dropping from 1080p to 720p on top of that is what turns a 200 MB clip into 20 MB.

Open Video Converter

Runs on your machine

Encoding happens locally, so long personal videos are not uploaded to a stranger's server just to be made smaller.

Open Video Trimmer

Step-by-step guide

How to use Video Compressor?

Shrink video file size for WhatsApp, email or web upload without a drastic quality drop.

Step-by-step instructions

1
Upload the video you want to compress.
2
Choose a target size or quality preset.
3
Optionally lower resolution (e.g. 1080p → 720p).
4
Click Compress and wait for encoding.
5
Download the smaller video.

Benefits

Massive size reduction (often 60–80%).
Resolution presets from 4K down to 360p.
In-browser FFmpeg — files never leave your device.
No watermark, no signup.

Who is it for?

Anyone sending videos on WhatsApp under 100 MB
YouTubers preparing preview clips
Students uploading video assignments

FAQ

Questions fréquentes

Open the site, click the blue "Choose File" button and pick a local .mp4, .mov, .avi, .mkv or .webm file. After the file loads, use the "Compression Preset" dropdown or the "Target Size (MB)" field to choose a final size, and set "Resolution" (4K, 1080p, 720p, 480p) if you want to downscale. Press "Start Compression"; progress runs in your browser and the page shows an estimated output size and expected bitrate. When finished click "Download" to save the compressed .mp4 by default (optional MOV/AVI output available if you toggle "Output Format").

The tool accepts .mp4, .mov, .avi, .mkv and .webm files as inputs; you can load HEVC (.mov/.mp4 with H.265) and VP9 content but browser codec support affects behavior. By default the compressor outputs an optimized .mp4 (H.264 + AAC) for maximum compatibility; you can choose to keep the original container when the codec is supported, or select "Output Format: MOV" or "AVI" for legacy needs. Note that alpha channels in ProRes/PNG-encoded MOVs are not preserved when converting to H.264 MP4; export will flatten transparency into standard video.

Because compression runs in your browser, practical limits depend on device memory: on desktop Chrome or Firefox we reliably process files up to ~1.5–2.0 GB, and smaller laptops may be fine up to ~1 GB. On macOS Safari and iOS Safari you'll see limits sooner — around 300–500 MB on older iPhones due to memory constraints; Android Chrome typically handles 500 MB–1.5 GB depending on free RAM. If a file is too large you'll get an "Out of memory" or "Failed to load file" message; in that case split the file or use a desktop browser with more RAM.

Yes — the tool performs in-browser compression so a 4K .mp4 or .mov is processed locally in your machine's browser without uploading to our servers. For 4K footage expect heavy CPU use and longer times; a 1-minute 4K clip (HEVC/H.264) might take 30 seconds to several minutes on a modern laptop depending on hardware and browser. Use Chrome or Firefox for faster WebCodecs/hardware-accelerated paths; Safari can be slower and more likely to hit memory limits on large 4K files. If you see slow performance, downscale to 1080p or 720p before compressing to reduce time and memory.

Click "Choose File", then set "Target Size (MB)" to the email limit you need — for Gmail set 25 MB, for stricter clients set 10–15 MB — and pick a lower resolution like 480p in the "Resolution" menu. The tool automatically adjusts bitrate to hit the target, but for best results manually choose H.264 MP4 and set resolution to 480p with a target bitrate around 800–1,200 kbps and AAC audio at 96 kbps. Remember email clients often cap attachments at 10–25 MB; if visual quality becomes unacceptable, split the video into shorter clips or share via cloud link instead.

Compression reduces bitrate and/or resolution; common practical targets are: 1080p — 5–8 Mbps, 720p — 2.5–4 Mbps, 480p — 800 kbps–1.5 Mbps, and 360p — 400–700 kbps. Audio at 96–128 kbps (AAC) is usually acceptable for speech and consumer video; reduce to 64 kbps only for podcasts or voice-only clips. Using a lower resolution gives the biggest size drop for minimal perceptible quality loss; aggressive bitrate caps will introduce blockiness and motion artifacts, so prefer downscaling plus moderate bitrate rather than tiny bitrate at original resolution.

No — Compress Video Online Free lets you compress videos without creating an account, and it does not add a watermark to the output MP4/MOV/AVI files for the free workflow. There are no forced paywalls for single-file browser compression; optional paid tiers (if shown) may add batch processing or higher file size allowances, but the basic in-browser compressor is free and usable immediately from the homepage. Because compression happens locally in your browser, there is no server-stamped watermark embedded during the normal workflow.

Those errors usually mean the browser ran out of memory or hit a codec limitation: switch to desktop Chrome or Firefox, close other tabs and background apps, and retry with a lower "Resolution" or smaller "Target Size (MB)". If the file uses an uncommon codec (ProRes, DNxHD) convert it first to a standard H.264 MP4 with a desktop tool or split the clip into smaller parts and compress each part separately. Also check browser console errors for messages about WebCodecs or MIME types; updating your browser to the latest version often fixes codec-related failures.

On Android Chrome you can usually compress files up to several hundred MBs with similar controls to desktop, but CPU and battery usage will be higher and the process may take longer. On iOS Safari limits are stricter: selecting large .mov/.mp4 files through the Files picker may fail above ~300–500 MB due to mobile memory and sandboxing; using a desktop is recommended for files larger than 500 MB. If you must use mobile, free up RAM (close apps), pick lower resolutions, or use Android devices with more RAM; the UI labels are the same but runtime constraints differ.

Most browser-side encoders do not preserve alpha channels when converting to H.264 MP4; if your MOV contains ProRes 4444 or Animation with alpha, the compressor will typically flatten transparency and output a standard opaque MP4. The "Output Format: MOV" option can retain container type but will only preserve alpha if the browser supports the original encoded codec and the encoder path supports alpha, which is rare in current in-browser tools. For projects requiring alpha (overlays, motion graphics), use a desktop tool like Adobe Media Encoder or export a PNG/ProRes 4444 MOV with your NLE instead.

HandBrake and VLC are full desktop transcoders with advanced features (2-pass encoding, CRF/Constant Quality, fine-grained audio mapping) and handle very large files reliably; they also support hardware acceleration and professional codecs like ProRes. The online tool excels at quick, single-file, in-browser compression without installs, and is great for one-off jobs up to ~1–2 GB; however it lacks 2-pass CRF tuning and batch workflows that HandBrake provides. For repeated professional output or maximum quality at tiny sizes, use HandBrake's CRF 18–23 or two-pass settings; use the online tool for speed and convenience when desktop installs are not available.

Compression is performed entirely in your browser, so the selected file is read from your local filesystem and processed on your device; by default we do not upload the source video to a remote server. Temporary data may exist in your browser's memory and inside the session tab; nothing is written to our servers unless you explicitly use a separate "Upload" or "Share" feature (which the free compressor does not require). If you want extra assurance, work offline with desktop tools, but the in-browser pipeline avoids transit to third-party servers under normal use.

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