Compress a video to a smaller file
Choose a compression strength, or type the file size you need, for example 25 MB for an email limit. VideoBB calculates the bitrate that fits, re-encodes to H.264 MP4 and can lower the resolution at the same time.
Free with a VideoBB account
Sign in with Google to use the video compressor. Your uploads and results stay private to you and are deleted after 24 hours.
How it works
File size is bitrate multiplied by duration. A compressor can only make a file smaller by spending fewer bits per second, so the useful question is where those bits are saved. Lowering the resolution saves the most with the least visible damage on phones; lowering quality at the same resolution shows first in dark scenes and fast motion.
Size mode works backwards from the number you give it: it divides the target by the video's duration, reserves 96 kbps for audio and gives the rest to video. Very small targets on long videos will look soft, and the tool says so rather than pretending otherwise.
Options at a glance
| Setting | What it does | Typical saving |
|---|---|---|
| Light | CRF 23, visually close to the source | 30-50% on phone and camera files |
| Medium | CRF 27, the everyday choice | 50-70% |
| Strong | CRF 31, soft but small | 70-85% |
| Target size | Two-pass encode at a bitrate calculated from your MB target | Just under your target, usually within about 3% |
| Max resolution | Also scales down, never up (measured on the short side) | Large extra saving on 4K sources |
Step by step
Upload
Drop the video. Up to 4 GB, resumable.
Choose
Pick a strength, or switch to target size and enter the MB you need.
Compress
Encoding runs in the background with a progress bar.
Download
Compare the new size, save it, or publish it to your channel.
When to compress a video, and when not to
Compress a video when it has to fit under a size cap. Email, chat apps, web forms and small drives all have one. The compressor trades detail for a smaller file, and you choose how far it goes.
Two other tools can shrink a file with less damage. If only part of the video matters, trimming the clip cuts the size in step with the length. If the file is going to a phone, lowering the resolution often saves more than squeezing the bitrate.
Skip compression before an upload to VideoBB. The site takes files up to 4 GB, and our guide to uploading large video files shows how to send them safely. VideoBB then builds its own quality levels from your original.
Quality level or target size?
The two modes answer different questions. Pick the one that matches your goal.
Quality level
- Best when you care most about how the video looks.
- The encoder uses CRF 23, 27 or 31, and the size lands where it lands.
- Sound is AAC at 128 kbps.
- Good for archives, share links and freeing up space.
Target size
- Best when you must stay under a fixed limit in MB.
- The tool works out a bitrate from your target and the length.
- Sound is AAC at 96 kbps to leave room for the picture.
- Good for email, upload forms and chat apps with a hard cap.
How the target size is worked out
The tool divides your target by the length of the video to get a bitrate. It keeps a 3% safety margin and sets 96 kbps aside for the sound. The rest goes to the picture.
It then encodes in two passes. The first pass studies the whole video, so the second pass can spread the bits where they are needed and land just under your number. If very busy footage still comes out over the target, the tool runs the second pass again at a lower bitrate.
Take a 3-minute video and a 25 MB target. That leaves about 1,000 kbps for the picture. That usually looks fine at 720p but soft at 1080p, so set the maximum resolution to 720p as well. The same 25 MB spread over 20 minutes leaves under 100 kbps, which looks rough at any size.
Common reasons to compress a video
Most people compress for one of three reasons. Each one suits a slightly different setting.
Getting under an email attachment limit
Many email services cap attachments at about 20 to 25 MB. Use Target size and aim a little under the cap, so the rest of the message still fits. For anything longer than a few minutes, a share link is kinder than an attachment.
Sending video in chat apps
Chat and messaging apps set their own upload caps, and those caps change over time. Check the current limit in the app, then use Target size with a small margin. Many apps also recompress what you send, so a clean starting file helps.
Saving space on a phone or drive
For storage, use Light or Medium rather than a target size. Quality then stays steady from scene to scene. The resolution stays the same unless you pick a lower one.
Fixing common compression problems
If the result is not what you expected, one of these is usually the cause.
The file came out larger than my target
Very small targets on long videos hit a floor. The tool never gives the picture less than 80 kbps, so the file can end up above your number, and the result says so. Trim the video, or accept a larger target.
The compressed file is bigger than the original
Quality mode aims at a look, not a size. A source that was already squeezed hard can grow. Use Strong or a target size instead.
Dark scenes and fast motion look blocky
Low bitrates hurt shadows and movement first. Lower the maximum resolution one step, so each pixel gets more data. Our overview of the video tools lists the other tools that can help.
Privacy and how long results stay
Compressed files are private to your account and are deleted 24 hours after the job. Each run counts toward your tool allowance: 10 jobs a day on a free account, 100 with Premium.
Frequently asked questions
Why do savings vary so much?
Phone and camera files are recorded at high bitrates to be safe, so they compress well. Screen recordings and animation compress extremely well. Files that were already compressed for the web have little left to remove.
How do I get a file under an email limit?
Switch to Target size and enter a number slightly below the limit, for example 23 MB for a 25 MB cap. If the result looks too soft, also lower the resolution to 720p or 480p.
Is the percentage in the table guaranteed?
No. They are typical ranges for common sources, not promises. The job page shows the real before and after size.
Can the maximum resolution make my video bigger?
No. It only scales down. A 720p video stays 720p even if you pick 1080p. The resolution is measured on the short side, so a 1080 by 1920 phone video counts as 1080p and keeps its size at 1080p.
Which codec does the compressor use?
It writes H.264 video and AAC sound in an MP4 file. H.264 plays on nearly every phone, browser and TV, so the smaller file stays easy to share.
Does compressing change the frame rate?
No. The frame rate stays the same. Only the bitrate changes, plus the resolution if you pick a lower one.
Related guides
More video tools
All toolsChange a video's format: MP4, WebM, MKV, MOV or AVI.
Trim videoCut a clip between two timestamps, instantly or frame-accurately.
Resize videoChange resolution from 4K down to 144p, keeping the aspect ratio.
Video to GIFTurn up to 30 seconds of video into a looping GIF.
Extract audioSave a video's soundtrack as MP3, M4A, WAV or Opus.
Mute videoRemove the audio track without re-encoding the picture.
Rotate or flip videoFix sideways or upside-down footage, or mirror it.