How to Compress Large Videos to Free Up Space on iPhone

TL;DR

CleanMaster shrinks large videos with efficient on-device HEVC compression — preview the quality options first, then export the smaller file straight back to your photo library, all without uploading.

Steps

In CleanMaster, open the video compressor and pick a large clip.
Choose a quality option and preview the trade-off.
Run the on-device HEVC compression.
Export the smaller file back to your photo library.
Delete the original if you no longer need it.

Why it works this way

Videos are the biggest single drain on iPhone storage, and a few 4K clips can outweigh thousands of photos. HEVC compression cuts their size substantially with little visible loss, and CleanMaster runs it on-device so even personal footage stays private. Previewing quality first means you decide the size-vs-quality balance, not an algorithm.

Tips & edge cases

Preview before saving — pick the quality that still looks good to you.
Delete the original afterward to actually reclaim the space.
Great before sharing large clips over messaging apps with size limits.

FAQ

Will compression ruin the quality? You preview quality options before saving, so you choose the balance of size and quality yourself.

Where does the compressed video go? Straight back to your photo library as a new, smaller file.

Is the video uploaded to compress it? No. Compression uses on-device HEVC encoding; the video never leaves your phone.