Question 1

How do I compress a video without losing quality?

Accepted Answer

You can't compress without any loss, but you can reduce size while keeping it visually similar. Use the balanced preset (CRF 23–28) — the difference is usually invisible for sharing on social media or messaging apps. Move the slider left only if you need a much smaller file and can accept lower quality.

Question 2

How much can I reduce my video file size?

Accepted Answer

Typically 50–90% depending on quality settings and the original video. Use the quality slider to balance size and quality. The estimated output size shows before you process.

Question 3

What's the best format for small videos?

Accepted Answer

MP4 with H.264 encoding gives the best combination of small file size and broad compatibility — it plays on Windows, Android, iOS, and the web. If file size is the top priority and compatibility is less critical, H.265/HEVC is smaller but not supported everywhere.

Question 4

Why does compression take long?

Accepted Answer

Browser-based processing uses your device CPU via WebAssembly, which is 3–5× slower than native software. Short clips compress in seconds; longer or high-resolution videos may take a few minutes. Trimming to the essential portion first significantly speeds things up.

Question 5

Why does compression sometimes fail?

Accepted Answer

Compression needs significant browser memory. For large or 4K videos: trim to a shorter segment first, increase compression, or reduce resolution. Very large files may exceed browser limits.

Question 6

Is my video private when compressing?

Accepted Answer

Yes. All compression happens in your browser. Nothing is uploaded to any server.

Compress video online — but keep it private (no uploads)

Frequently Asked Questions