What this tool does
Reduce video file size without uploading the source to ToolsDiary. The compressor plays and re-encodes the video locally in your browser, lets you choose a quality preset and target resolution, and then shows the original size, output size and percentage saved before you download the new file.
Browser video encoding is more demanding than image compression. Processing usually takes roughly the length of the video and depends on your device, browser and available codecs. The tool automatically selects a recording format supported by your browser, commonly MP4 or WebM, rather than pretending every browser can create the same codec combination.
Useful for
- Reduce video size before uploading to a website, CMS or messaging service.
- Create smaller copies of screen recordings, demos and short social videos.
- Downscale large 4K or 1080p files when a smaller delivery resolution is enough.
How to use it
- Choose a video from your device and wait for its duration and dimensions to appear.
- Select High Quality, Balanced or Maximum Compression, then choose the original, 1080p, 720p or 480p resolution.
- Start compression and keep the page open while the browser re-encodes the video locally.
- Preview the result, compare the file sizes and download it only if the quality and saving are acceptable.
Practical tips
- Balanced is a practical starting point for most web and social-media uploads.
- Reducing resolution often saves more space than lowering bitrate while keeping a very large frame size.
- Keep the original file because browser re-encoding is a new lossy generation and may remove metadata.
- For long or very large videos, a desktop video editor or native FFmpeg workflow can be much faster than browser processing.
Frequently asked questions
Are my videos uploaded to ToolsDiary?
No. This version reads and re-encodes supported videos in your browser. The source file and generated output are not uploaded to ToolsDiary.
Why does compression take a long time?
The browser has to decode, scale and encode the video on your device. This implementation processes in real time, so a five-minute video can take about five minutes plus setup and finalization time.
Will the output always be MP4?
No. The tool detects formats that your browser can record. Some browsers can create MP4 while others may create WebM. The result area shows the actual format used.
Can a compressed video become larger?
Yes. A source that is already efficiently compressed can produce a similar or larger file. The tool reports the result clearly so you can keep the original when compression does not help.