What does Video Compressor do?
Reduce the file size of an MP4, MOV or WebM video in your browser, without uploading it. Choose output quality and resolution, or set an approximate target size, then compare the original and compressed files before downloading. Lower resolution removes pixels while stronger compression spends fewer bits on each frame; either can reduce size, but both may affect detail. Export a local MP4 or WebM without a watermark.
How to use Video Compressor
- 1Choose an MP4, MOV or WebM video.
- 2Pick a quality preset and output resolution, or enter an approximate target size.
- 3Review the estimated size and codec settings.
- 4Compress locally, preview the result and download it if the reduction is useful.
Supported inputs and outputs
Inputs
MP4, MOV, WebM
Outputs
MP4 (H.264/AAC), WebM (VP9/Opus)
Practical uses
- Reducing upload time
- Preparing review copies
- Fitting a video into a message attachment
- Lowering archive storage
Browser and media limitations
- Target-size estimates are approximate.
- Already-compressed sources may become larger.
- VP9 encoding can be slow and Safari support varies.
- Upscaling does not create new detail.
How local processing works
Processing runs locally in your browser with FFmpeg.wasm. The media engine is downloaded on first use, but your media is not sent to Tubelexity or a processing server.
How quality, resolution and target size interact
A lower bitrate usually makes a smaller video by spending fewer bits on the same frames, which can introduce blockiness or smearing. Lowering resolution reduces the number of pixels the encoder must store and often makes a bigger size difference, but fine details will be lost if the video is later viewed large. For a small shareable copy, reducing dimensions modestly can be preferable to forcing very low quality at full resolution.
A target size is an estimate, not an exact cap: duration, audio, container overhead and scene complexity affect the result. Start with a quality preset, inspect the preview and actual output size, then lower resolution or frame rate only if the file is still too large. An already efficient source can become larger after re-encoding.
Frequently asked questions
How do I compress a video online for free?
Choose an MP4, MOV or WebM file, select quality and resolution or an approximate target size, then process and compare the downloaded result. The video stays in your browser.
Is the target file size exact?
No. The tool calculates a bitrate after reserving audio and container overhead, but source complexity changes the final size.
Which output has the widest support?
MP4 with H.264 video and AAC audio is usually the most broadly playable option.
Does compression reduce quality?
Re-encoding can reduce quality. Higher quality and resolution settings preserve more detail but produce larger files.
Does lowering video resolution reduce file size?
It usually can because fewer pixels need encoding. If the video must stay sharp at its original display size, try a modest quality reduction first and compare the preview.
What if the compressed file is larger?
Tubelexity warns you and keeps the original available when compression provides no useful reduction.