katana-video/webcodecs-codec-support

The Codec Support Dataset

Version 2026-10-01

Dataset Summary

This dataset contains real-world audio and video codec support data passively collected from 7,655,853 unique user sessions at free.upscaler.video, an open-source browser-based video upscaler with ~700,000 monthly active users. Each session uses the WebCodecs API (VideoEncoder.isConfigSupported() / VideoDecoder.isConfigSupported() and their audio equivalents) to test encoding and decoding support for a random sample of ~300 out of 1,087 codec strings across the major codec families (H.264, H.265, VP8, VP9, AV1, AAC, Opus, etc.).

• Total Tests: 2,434,549,264
• Sessions: 7,655,853
• Unique Codecs: 1,087
• Collection Period: January 2, 2026 – October 1, 2026
• Format: Parquet (zstd), one file per month, 3.85 GB total
• DOI (all versions): 10.5281/zenodo.19187466

The data is summarized interactively at webcodecsfundamentals.org, with a per-codec support table and an analysis of AV1, HEVC, VP9 and H.264 support.

Files

File	Days	Rows
data/codec-support-2026-01.parquet	30	138,596,578
data/codec-support-2026-02.parquet	27	81,443,298
data/codec-support-2026-03.parquet	31	201,598,644
data/codec-support-2026-04.parquet	30	197,135,832
data/codec-support-2026-05.parquet	31	236,605,038
data/codec-support-2026-06.parquet	30	281,177,508
data/codec-support-2026-07.parquet	31	343,646,700
data/codec-support-2026-08.parquet	31	454,035,630
data/codec-support-2026-09.parquet	30	484,965,900
data/codec-support-2026-10.parquet	1	15,344,136

SHA256SUMS contains checksums for every file.

Dataset Structure

One row per codec test (one codec string tested in one session). Rows from the same session are contiguous.

Column	Type	Description
session_id	string	Unique ID of the test session
timestamp	timestamp (ms, UTC)	When the session's tests were run
user_agent	string	Full browser user agent string
browser	string	Browser family (Chrome, Safari, Edge, Firefox, Unknown)
platform_raw	string	Raw navigator.platform value
platform	string	Normalized platform (Windows, macOS, iOS, Android, Linux, Other)
codec	string	WebCodecs codec string tested (e.g. av01.0.16M.08)
encoder_supported	bool	Whether the encoder supports this codec
decoder_supported	bool, nullable	Whether the decoder supports this codec; null if not tested

decoder_supported is null for sessions before January 14, 2026, when decoder testing was added (98% of sessions include decoder data). browser is reported by the client; all Chromium-based browsers other than Edge (Brave, Opera, Samsung Internet, etc.) are grouped as Chrome.

Platform Normalization

• Win32, Win64, WIN32 ➔ Windows
• MacIntel, MacOS, Mac OS ➔ macOS
• iPhone, iPad ➔ iOS
• Linux armv7l, Linux armv8l, Linux armv81, Linux armv6l, Linux arm, Android, Android64 ➔ Android
• Linux, Linux x86_64, Linux aarch64, Linux amd64, Linux i686 ➔ Linux
• Anything else (e.g. HarmonyOS, blank, spoofed values) ➔ Other (18 sessions)

Usage

At 2.4 billion rows the dataset is too large to load into pandas; query the files in place with DuckDB, Polars or Spark:

import duckdb

con = duckdb.connect()
con.sql("CREATE VIEW tests AS SELECT * FROM read_parquet('data/*.parquet')")

# Encoder and decoder support by codec
con.sql("""
    SELECT codec,
           round(100 * avg(encoder_supported::INT), 2) AS encoder_pct,
           round(100 * avg(decoder_supported::INT), 2) AS decoder_pct,
           count(*) AS tests
    FROM tests
    GROUP BY codec
    ORDER BY encoder_pct DESC
""").show()

With Hugging Face datasets, use streaming rather than downloading everything up front:

from datasets import load_dataset

ds = load_dataset("katana-video/webcodecs-codec-support", split="train", streaming=True)

Dataset Creation & Methodology

Data is collected anonymously in the background on free.upscaler.video. No personally identifiable information is collected: only the user agent, navigator.platform, and codec test results. A full description of the collection methodology is here.

Known Limitations

• Sessions, not devices. Percentages are per session and reflect free.upscaler.video's traffic mix (77% Chrome, 50% Windows, 30% Android). Reweight by your own traffic for other applications.
• WebCodecs API support, not hardware support. A codec the device supports may be missing from the WebCodecs API (e.g. Firefox on Android does not expose WebCodecs), so the numbers are conservative.
• isConfigSupported() only. Results do not measure encode/decode performance or quality.
• Collection gap. Very few sessions were recorded between February 8 and February 20, 2026 (none on February 19) due to a collection outage.

Changes from Version 2026-03-22

• 7,655,853 sessions (was 1,142,586), collection period extended to October 1, 2026

• Parquet instead of CSV (3.85 GB instead of 69.4 GB uncompressed)

• New session_id column

• Platform normalization extended to rare navigator.platform values, with an Other bucket

• Producer: Katana Video Inc.

• Author: Samrat Bhattacharyya

Citation Information

@dataset{upscaler_codec_dataset_2026,
  title        = {The Codec Support Dataset},
  author       = {Bhattacharyya, Samrat},
  year         = {2026},
  version      = {2026-10-01},
  publisher    = {Zenodo},
  doi          = {10.5281/zenodo.19187466},
  url          = {https://doi.org/10.5281/zenodo.19187466},
  note         = {2.43B codec tests from 7.66M sessions}
}

License

Creative Commons Attribution 4.0 International (CC-BY 4.0). Credit "The Codec Support Dataset" with a link to webcodecsfundamentals.org/datasets/codec-support.