Phones record video at high bitrates because storage is cheap and quality matters at the moment of capture. The bill arrives later, when a two-minute clip is too big for an email, a form rejects the upload, or a chat app refuses the file. Most of that size can go without anyone noticing on a phone or laptop screen.
This compressor re-encodes MP4, MOV, WebM, MKV and AVI files to an efficient H.264 MP4. Choose how hard to compress, or type the size you need in megabytes, optionally lower the maximum resolution, and press Convert. The result list shows how much smaller each file became. Your videos stay on your device throughout.
Where the savings in a compressed video come from
Video size is bitrate multiplied by duration. A modern phone often records 1080p at 15 to 20 megabits per second, which is well over 100 MB per minute, and 4K at several times that. An encoder can describe the same picture with far fewer bits by spending effort on what changes between frames and accepting slightly softer fine detail. Re-encoding at a sensible quality setting commonly cuts phone footage to a third or less of its original size.
The second lever is resolution. Fewer pixels need fewer bits for the same sharpness, so a clip that will only be watched in a chat window gains little from being 4K. Lowering the resolution and compressing together usually beats compressing alone when the target is small. If you need specific dimensions rather than a smaller file, Resize Video is the better tool.
Typical reasons to compress a video
Fitting an email or form limit
Email services commonly cap attachments at 20 to 25 MB, and attachments grow by about a third when they are encoded for sending. Choosing Target size with a value well below the limit, such as 18 MB, gives the most reliable result.
Sending through chat and messaging apps
Apps that compress videos themselves often do it harshly. Compressing first with Light or Medium gives you control over how the clip looks when it arrives.
Saving storage on long recordings
Screen recordings, lectures and family videos can take gigabytes. Medium or Strong with a 720p cap shrinks them a lot, and talking-head or slide content still reads clearly.
The presets and the target size explained
Every option encodes H.264 video and AAC sound into MP4, which plays almost everywhere. The presets use constant quality rather than a fixed bitrate, so simple scenes take fewer bits than busy ones: Light (quality level 23, 128 kbps audio) is barely distinguishable from a good source, Medium (28, 96 kbps) is the default and suits most sharing, and Strong (32, 64 kbps) gives the smallest files with visible softening. Maximum resolution can bring the short side down to 1080, 720 or 480 pixels, works for portrait and landscape alike, and never enlarges a smaller video.
Target size first reads the video's length, then caps the bitrate so that video plus audio fit about 95 percent of the megabytes you typed, leaving room for the container. The sound gets 128, 96, 64 or 32 kbps depending on the budget. The size is approximate: simple footage often lands below the target because the quality limit is reached first, and a target too small for the length cannot be met, since the video never drops under 50 kbps. As a guide, 25 MB allows roughly 1 Mbps for a three-minute clip but only about 330 kbps for ten minutes, where a 480p cap helps. Encoding runs in the browser with the site's ffmpeg-based converter, a 31 MB download on first use, on one processor thread.
Come usare questo strumento
- Drop one or more MP4, MOV, WebM, MKV or AVI files on the box above, or click it to choose them.
- Under Compression, pick Light, Medium or Strong, or choose Target size and type the size in Target size (MB).
- Optionally set Maximum resolution to 1080p, 720p or 480p.
- Press Convert. The first run downloads the converter; each file then shows its progress and how much smaller it became.
- Download the MP4 files one at a time or with Download all (.zip).
Limitations
- The output is always MP4, even for WebM, MKV or AVI sources.
- Already efficient files, such as videos downloaded from streaming sites, may barely shrink, and Light can occasionally produce a larger file. The result list says so with a percentage.
- Target size is an estimate, not a guarantee, and very small targets for long videos come out larger than asked.
- Encoding is slow compared with desktop software: a long 4K video can take many minutes, especially on a phone. Files can be up to 500 MB each.