Free Online Video Compressor

Video compression without the headache — what CRF and resolution actually mean for you

Most people just want a smaller video. They don't care about codecs. But knowing two things — CRF and resolution — will save you a lot of trial and error, because they're the only settings that actually matter for 95% of compression jobs.

CRF (Constant Rate Factor) is a quality dial. It runs from 0 (perfect, massive file) to 51 (terrible, tiny file). H.264 at CRF 23 is the sweet spot most streaming sites use internally. You won't see quality loss at CRF 23 on a normal screen. Push to CRF 28 and files get genuinely small — still watchable for most content. CRF 32+ starts showing blocks and smearing in fast-motion scenes.

Resolution is the other lever. Dropping from 1080p to 720p cuts pixel count by more than half, which means the encoder has far less to store. For anything that'll be watched on a phone or embedded in a webpage, 720p is more than enough.

What CRF values to actually use

• CRF 18–20 — archive quality. Files are still large but visually perfect. Use this if you're keeping a master copy and storage isn't a concern.
• CRF 23–25 — the practical sweet spot. This is what YouTube, Vimeo, and most streaming platforms target. Looks great on any screen.
• CRF 28–30 — small and still perfectly watchable for talking-head videos, screencasts, or anything without fast motion.
• CRF 32+ — aggressively small. You'll notice quality loss in sport footage, action games, or anything with camera shake. Fine for previews or rough cuts.

H.264 vs H.265 — should you bother with H.265?

H.265 (HEVC) delivers the same visual quality as H.264 at roughly half the file size. That sounds great. The catch is compatibility: older Smart TVs, budget Android devices, and anything running Windows 7 may not play HEVC natively. If you're sharing the file with people on unknown devices, stick with H.264. If it's for your own use or a controlled environment, H.265 is genuinely worth it — especially for 4K content where the size difference is dramatic.

Why your phone video is already compressed — and what that means for re-compression

Your iPhone and most Android phones shoot in H.264 or H.265 at 60–100 Mbps. That's already heavily compressed compared to raw camera footage, but it's still much larger than what you need for sharing. Re-compressing to 8–15 Mbps at the same resolution looks identical for casual viewing and cuts the file to a tenth of its original size. Going lower than 4 Mbps at 1080p is where most people start noticing softness in fast-moving scenes.

When to drop resolution vs just raise CRF

Dropping resolution is a more aggressive move than raising CRF — you're permanently reducing detail level. But it's often the right call. A 4K video doesn't need to be 4K if your audience watches on phones. 720p at CRF 22 will look sharper and cleaner than 1080p at CRF 32, and the file will be smaller too. When in doubt: try keeping the resolution and raising CRF first. Only drop resolution if the CRF target still isn't hitting your size goal.

Compressing for specific platforms

WhatsApp

16 MB limit for video messages. A 3-minute clip at 720p with CRF 28 usually lands around 10–15 MB. If it's still too big, try 480p.

Discord

8 MB for free accounts, 50 MB for Nitro. Short clips compress well to H.264 at 720p, CRF 28. Keep clips under 90 seconds for free accounts.

Email

Most email providers cap attachments at 25 MB. A 5-minute 1080p video typically needs to be at 720p with CRF 28 to fit. Anything over 10 minutes is better shared via a link.

Instagram / TikTok

These platforms re-compress your upload anyway, so there's no point sending them a massive file. 1080p at CRF 23 is more than enough — they'll downscale it themselves on delivery.

Container format: MP4 is the safe choice

The output is MP4 regardless of whether you compress with H.264 or H.265. MP4 is the most universally supported video container — it plays on every browser, every phone, every Smart TV, and every social media platform without issues. If your source is MKV or WebM, the container change alone will fix playback on devices that didn't support the original format.