README.md

---
license: cc-by-4.0
task_categories:
- tabular-classification
tags:
- webcodecs
- video-processing
- hardware-acceleration
- telemetry
- browser-support
- av1
- h265
- hevc
- vp9
- h264
pretty_name: WebCodecs Codec Support Dataset
size_categories:
- 1B<n<10B
configs:
- config_name: default
  data_files:
  - split: train
    path: data/*.parquet
---

# 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](https://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](https://doi.org/10.5281/zenodo.19187466)

The data is summarized interactively at [webcodecsfundamentals.org](https://webcodecsfundamentals.org/datasets/codec-support/), with a per-codec [support table](https://webcodecsfundamentals.org/datasets/codec-support-table/) and an [analysis of AV1, HEVC, VP9 and H.264 support](https://webcodecsfundamentals.org/datasets/codec-analysis-2026/).

## 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](https://duckdb.org/), Polars or Spark:

```python
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:

```python
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](https://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](https://free.upscaler.video/research/methodology/).

### 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

```bibtex
@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)](https://creativecommons.org/licenses/by/4.0/). Credit "The Codec Support Dataset" with a link to [webcodecsfundamentals.org/datasets/codec-support](https://webcodecsfundamentals.org/datasets/codec-support/).