Compress an MP4
Choose how big you want the file to be, or pick a percentage of the original. Altols re-encodes the picture with H.264 and copies the audio across untouched, so speech and music don't lose quality.
MP4, MOV or M4V. Free up to 100 MB. Your video stays on your device.
How it works
- Choose a video. It stays on your device.
- Pick the size you need. Altols works out the bitrate and resolution that fit.
- Your browser re-encodes the picture as H.264 and copies the sound across untouched.
- Download the MP4.
Frequently asked questions
Does it change the audio?
No. The audio track is copied across as it is, so it keeps its original quality. Only the video is re-encoded.
Why is the output bigger than I expected?
If your target is close to the original size, there is nothing to gain. Altols tells you when a file is already smaller than the target.
Is my video uploaded anywhere?
No. Altols uses your browser's built-in video encoder, so the video is processed on your device and never leaves it.
Is there a size limit?
Free compression works on videos up to 100 MB. For larger videos, up to 1 GB, a 24-hour pass costs $2.99 USD.