How to Compress a Video and Estimate File Size

Set a realistic size goal

Start with the platform upload limit, storage budget, or sharing method. Keep the original master if you may edit again; a compressed file is a delivery copy.

Inputs use common video containers, are limited to 10 GB, and must have a short edge no larger than 2160 pixels. Each file must pass media validation.

Balance compatibility and compression

Choose H.264 for broader compatibility or H.265 when target devices support it. Then choose one of three presets. The preset selects a target bitrate; there is no manual bitrate or target-megabyte control.

Output is MP4, keeps input dimensions and frame rate, and converts audio to AAC. HDR input is converted to SDR. H.265 playback depends on the browser, operating system, and device.

Treat the estimate as a planning aid

The estimate uses input size, duration, and preset. It cannot account perfectly for visual complexity, audio, or container overhead, so the final size may differ.

Review the credit quote separately. Estimated file size is not a billing promise or a maximum-size guarantee.

Inspect playback and final size

Check the real file size, picture quality, and sound. Compare detailed scenes and motion, then play the file on the device or platform where you plan to share it.

The finished MP4 is limited to 2 GB. If H.265 does not play on a target device, create an H.264 version for that delivery path.

• Check actual size instead of relying on the estimate.
• Look for blocking, banding, or detail loss in motion and gradients.
• Test audio sync and playback on the intended device.