H.264 vs HEVC (H.265): Which Video Codec Should You Choose?

tldr:

Every compressed video is written in a codec — the grammar that describes how frames are encoded. For the last two decades two codecs have mattered most: H.264 (AVC), the universal default, and HEVC (H.265), its more efficient successor.

Pick the wrong one and you either waste 40% of your possible savings — or produce a file that won’t play on your dad’s laptop. Here’s how to choose.

What a codec actually is

A video codec defines how each frame is compressed: which pixels can be predicted from earlier frames, how motion is estimated, and how much error the decoder tolerates. A better codec achieves the same visual quality with fewer bits — HEVC needs roughly 30–50% less bitrate than H.264 for visually equivalent output.

H.264 (AVC)HEVC (H.265)
Introduced20032013
Same quality vs H.264baseline~30–50% smaller
CompatibilityEverything, everywhereMost modern devices
Playback on old devices⚠️ Often no
Hardware encode on phones✅ (most phones since ~2016)
Best forSharing with anyonePersonal archives, modern devices

Why HEVC is smaller: the engineering in one minute

Both codecs predict frames from neighboring frames. HEVC does it with finer tools: larger, flexible block sizes (up to 64×64 vs H.264’s 16×16), better motion compensation, and smarter intra-prediction modes. The result is fewer bits spent describing the same scene.

For the mathematically inclined: encoding the same 1080p clip at the same visual quality might cost H.264 10 Mbps and HEVC 6 Mbps — a 40% saving on the entire file, for free.

The compatibility question (the only reason this is a debate)

HEVC patents and licensing kept it out of the web’s core for a decade. The practical fallout:

Translation: HEVC files are safe when you control the playback environment — your own devices, your family’s recent iPhones. The moment a file goes to “someone unknown,” H.264 remains the only universally safe choice.

How your phone’s hardware fits in

Your phone has dedicated silicon for encoding video — the same hardware the camera app uses. Both H.264 and HEVC encode through it, which means:

This is why Kompress uses the platform’s own encoders (AVFoundation on iOS, MediaCodec on Android) instead of bundling FFmpeg: same hardware path your camera already trusts, in a small app.

The decision, in three cases

1. Compressing videos you’ll share with othersH.264. Guaranteed playback everywhere: every phone, browser, TV, laptop, and messaging app. The slightly larger file is the price of certainty.

2. Compressing videos you’ll keep for yourselfHEVC, if your devices are modern. You’re the playback environment; enjoy the extra 30–40% savings on your archive.

3. Storage emergency, any playback → HEVC where it works, H.264 fallback. In Kompress, Advanced mode exposes the choice; if a device can’t encode HEVC, the app falls back to H.264 automatically and tells you — you never get a file that silently won’t play.

A note on “future-proofing”

H.265’s successor momentum (AV1) is real in streaming, but AV1 encoding on phones is still slow and rare. For files you create yourself on a phone in 2026, H.264 and HEVC remain the practical pair. Don’t over-think codecs you can’t encode with the hardware you own.

Bottom line

Want to try both? Kompress exposes the codec switch in Advanced mode, compresses on-device, and shows a before/after comparison so you can judge the results yourself. The first run is free on the App Store and Google Play.

Keep reading