Compare video codecs

Four codecs cover nearly every video delivery scenario. Here is how they compare on the metrics that matter.

Benchmark comparison

All numbers are relative to h264 at the same visual quality (VMAF ~95).

Codec	Container	Browser support	Relative file size	Encode speed	Decode complexity	Licensing
`h264`	mp4	Universal	1.0x (baseline)	1.0x (baseline)	Low	Licensed
`h265`	mp4	Safari, Edge, Chrome (partial)	~0.7x	~0.5x	Medium	Licensed (royalties)
`vp9`	webm	Chrome, Firefox, Edge	~0.7x	~0.4x	Medium	Royalty-free
`av1`	mp4, webm	Chrome, Firefox, Edge, Safari 17+	~0.6x	~0.15x*	High	Royalty-free

*Sequential encode speed. Ittybit parallelizes AV1 encoding across chunks, bringing wall-clock time much closer to h264.

Encode the same clip with each codec

Take a 1080p 60-second source and encode it four ways:

# h264 -- universal baseline
ittybit video \
  -i source.mov \
  -o output-h264.mp4 \
  --codec h264 \
  --quality high

# h265 -- smaller, Apple/Android native
ittybit video \
  -i source.mov \
  -o output-h265.mp4 \
  --codec h265 \
  --quality high

# vp9 -- royalty-free, Chrome/Firefox
ittybit video \
  -i source.mov \
  -o output-vp9.webm \
  --codec vp9 \
  --quality high

# av1 -- smallest files, modern browsers
ittybit video \
  -i source.mov \
  -o output-av1.mp4 \
  --codec av1 \
  --quality high

Typical results (1080p, 60s, high quality)

Codec	Output file	Approx. size	Encode time (local)
`h264`	output-h264.mp4	~25 MB	~8s
`h265`	output-h265.mp4	~18 MB	~16s
`vp9`	output-vp9.webm	~17 MB	~20s
`av1`	output-av1.mp4	~15 MB	~55s

Results vary by content. High-motion footage benefits more from newer codecs. Talking-head video shows smaller differences.

Browser support matrix

Browser	h264	h265	VP9	AV1
Chrome 70+	Yes	Partial	Yes	Yes
Firefox 67+	Yes	No	Yes	Yes
Safari 17+	Yes	Yes	No	Yes
Safari < 17	Yes	Yes	No	No
Edge 79+	Yes	Yes	Yes	Yes
iOS Safari	Yes	Yes	No	17+
Android Chrome	Yes	Yes	Yes	Yes

When to pick what

Scenario	Best codec	Why
Maximum compatibility	h264	Plays everywhere, no exceptions
Bandwidth-sensitive web	AV1	Smallest files, modern browser coverage
Native iOS/Android app	h265	Hardware decode, no browser involved
Open-source project	VP9	Royalty-free, good browser support
Archive / cold storage	AV1	Best compression, decode speed irrelevant
High-volume / fast turnaround	h264	Cheapest to encode at scale