H.264 vs H.265 vs VP9

A codec is the method used to store the picture. All three of these do the same broad job; they differ in how cleverly, and in who is allowed to use them without paying.

Why H.264 still wins by default

It is twenty years old and less efficient than either successor, and it plays on literally everything: every browser, every phone, every television, every editing program, every upload form. When a file has to work rather than be small, that is worth more than 40% efficiency.

Where H.265 and VP9 fit

H.265 delivers the biggest saving and carries the messiest licensing, which is why it took hold in hardware — Apple devices, broadcast, 4K delivery — and never became a web default.

VP9 is royalty-free, which is exactly why Google could deploy it across YouTube and the browsers could support it without negotiation. On the web it is well supported; hand a .webm to a colleague to open in desktop software and you may get a shrug.

Choosing in practice

• Sending a file to a person, or uploading to a platform — MP4 with H.264. It cannot be refused.
• Serving video on your own web page — WebM with VP9 is smaller at the same quality, and every current browser plays it.
• Archiving 4K footage where storage is the constraint — H.265, using software that can encode it.

Mistakes worth avoiding

• Sending a WebM to someone who did not ask for one. It may not open outside a browser.
• Re-encoding H.264 to VP9 to "save space" on a file you already have. You lose a generation of quality for a saving that only applies if you were encoding from a master.
• Comparing CRF numbers between codecs.