What This Tool Does
This tool reduces a video's file size by re-encoding it at a chosen quality level. Upload a video, choose how much to compress it, and download a smaller version — useful for fitting files within upload limits or reducing storage and sharing time.
Common Reasons to Compress Video
- Email and messaging limits: many platforms restrict video attachment sizes, and compression can bring a file under that limit
- Faster uploads: smaller files upload more quickly, especially on slower connections
- Saving storage: reducing the size of recordings you want to keep without using as much space
- Sharing over messaging apps: some apps compress videos automatically and reduce quality unpredictably — compressing yourself first gives more control
How to Compress a Video — Step by Step
- Upload your video by dragging it into the upload area or clicking to browse
- Choose a compression level — higher compression means a smaller file but more visible quality loss
- Click Compress Video
- Review the size reduction and preview the result
- Download the compressed video
Processing happens entirely in your browser using a built-in video processing engine — your video is never uploaded to a server. The first time you use any of our video tools, there's a one-time download of this processing engine (around 30MB), cached afterward for instant use. Note that video compression re-encodes the file and can take a noticeably longer time than other video tools — for longer videos, this can take several minutes.
Understanding Quality Levels
This tool uses CRF (Constant Rate Factor) encoding, where a lower number means higher quality and a larger file, and a higher number means more compression and a smaller file. The presets offered map to commonly-used CRF values: Light compression keeps quality very close to the original with a modest size reduction; Balanced offers a good trade-off for most sharing purposes; Maximum compression produces the smallest files but with more visible quality loss, particularly in scenes with motion or fine detail.
Why Some Videos Compress Better Than Others
The same compression setting can produce very different size reductions depending on the footage. Video compression works partly by identifying similarities between consecutive frames and storing only the differences — footage with a static camera and minimal movement (a talking-head video, a screen recording of mostly-still content) has a lot of similarity between frames and compresses very efficiently. Footage with constant motion — handheld camera movement, fast action, busy scenes with lots of detail changing every frame — has much less similarity between consecutive frames, so the compression has less redundancy to exploit and the resulting file remains comparatively larger even at the same quality setting. If you're compressing footage that falls into this second category and the result is larger than expected, this is a normal consequence of the content itself rather than something being done incorrectly.
How Long Will It Take?
Unlike trimming or muting, compression requires re-encoding every frame, which is computationally intensive. Processing time depends on your video's length, resolution, and your device's processing power — a short clip might take under a minute, while longer or higher-resolution videos can take several minutes. Keep the browser tab open and active while processing.
Compression Versus Resizing for Reducing File Size
Compression and resizing both reduce file size, but in different ways, and combining them often produces better results than either alone. Compression reduces size by encoding the existing resolution more efficiently (with some quality trade-off at higher compression levels); resizing reduces size by reducing the actual number of pixels that need to be encoded at all. For a video that's much higher resolution than needed for its destination — say, a 4K recording that will be shared for viewing on phones — resizing down to 1080p with our Video Resizer first, and then applying moderate compression to the smaller-resolution result, often achieves a smaller final file with better visual quality than applying heavy compression to the original high resolution alone.
Related Tools
If you only need to trim the video first to reduce what needs compressing, use Video Trimmer before compressing. If file size isn't the issue but you need a different format, that would require a format conversion workflow.
Frequently Asked Questions
How much smaller will my video be?+
This depends on the original video and the compression level chosen. Videos with a lot of motion or detail compress less efficiently than simpler footage. The tool shows the size reduction after processing.
Why does compression take longer than other video tools?+
Compression re-encodes every frame of the video, which is computationally intensive, unlike trimming or muting which can copy data without re-encoding.
Will compression always reduce quality?+
Some quality reduction is inherent to compression, though at lighter settings this is often difficult to notice. Higher compression levels trade more visible quality for smaller files.
Is there a file size limit?+
Files up to 100MB are supported as input. Larger or longer videos take proportionally longer to compress.
Is my video uploaded anywhere?+
No, processing happens entirely within your browser.