| --- |
| license: cc-by-4.0 |
| language: |
| - en |
| pretty_name: "Developer Reference Datasets: Aspect Ratios, WCAG Contrast, MIME, Encoding, QR" |
| tags: |
| - aspect-ratio |
| - screen-resolution |
| - wcag |
| - accessibility |
| - color-contrast |
| - mime-types |
| - magic-numbers |
| - character-encoding |
| - utf-8 |
| - qr-code |
| - web-development |
| - reference |
| size_categories: |
| - n<1K |
| configs: |
| - config_name: aspect-ratios |
| data_files: aspect-ratios.csv |
| - config_name: resolutions |
| data_files: resolutions.csv |
| - config_name: wcag-contrast-pairs |
| data_files: wcag-contrast-pairs.csv |
| - config_name: wcag-on-white-black |
| data_files: wcag-on-white-black.csv |
| - config_name: encoding-sizes |
| data_files: encoding-sizes.csv |
| - config_name: file-types |
| data_files: file-types.csv |
| - config_name: favicon-icon-sizes |
| data_files: favicon-icon-sizes.csv |
| - config_name: social-media-image-sizes |
| data_files: social-media-image-sizes.csv |
| - config_name: qr-code-capacity |
| data_files: qr-code-capacity.csv |
| - config_name: image-format-support |
| data_files: image-format-support.csv |
| --- |
| |
| # Developer Reference Datasets |
|
|
| <img src="https://raw.githubusercontent.com/cleanor-app/developer-reference-datasets/main/docs/kaggle/cover.png" alt="Developer Reference Datasets: aspect ratios, WCAG contrast, MIME, encoding, QR, format support" width="720"> |
|
|
| Open, reproducible lookup tables that web and app developers reach for constantly — **computed from first principles, not scraped, so every value is exact and re-runnable.** CC BY 4.0. |
|
|
| ## Quick answers (straight from the data) |
|
|
| - **What is 16:9 in pixels?** 1920×1080, 1280×720, 3840×2160. 9:16 (Stories, Reels, TikTok) is those flipped. → `aspect-ratios`, `resolutions` |
| - **What contrast ratio does WCAG require?** 4.5:1 for normal text (AA), 3:1 for large, 7:1 for AAA. `#6b7280` on white is 4.83 (passes AA); `#9ca3af` is 2.54 (fails). → `wcag-contrast-pairs`, `wcag-on-white-black` |
| - **How many bytes is a character?** In UTF-8: Latin 1, accented/Greek/Cyrillic 2, CJK 3, most emoji 4 (a flag emoji is 8 bytes / 2 code points). → `encoding-sizes` |
| - **What is the MIME type / magic number of a file?** Extension → MIME type + byte signature, **with the offset** (RIFF/ISO-BMFF/tar signatures are not at byte 0, which most lists get wrong). `.docx` is a ZIP (`PK`). → `file-types` |
| - **How many characters fit in a QR code?** A version-1 QR holds 41 digits / 25 alphanumeric / 17 bytes at ECC level L; up to 7,089 digits at version 40. Computed from ISO/IEC 18004, verified. → `qr-code-capacity` |
| - **Which browsers support AVIF / WebP / JPEG XL?** AVIF is fully supported since Chrome 85, Firefox 93, Safari 16.4; JPEG XL is fully supported nowhere. → `image-format-support` |
| - Plus favicon/app-icon sizes per platform and current social-media image sizes (date-stamped). |
|
|
| ## Why it's trustworthy |
|
|
| These are exact answers from the spec, not measurements. An aspect ratio, a WCAG contrast ratio, a UTF-8 byte count and a QR capacity are computable — so the CSVs are computed and re-runnable, and checkable against any online tool. |
|
|
| - **Cite:** DOI [10.5281/zenodo.21369536](https://doi.org/10.5281/zenodo.21369536) (concept DOI, all versions, CC BY 4.0, Cleanor Labs) |
| - **Code + methodology:** https://github.com/cleanor-app/developer-reference-datasets |
| - **Human-readable write-ups:** https://cleanor.app/research/open-datasets |
| - **License:** CC BY 4.0 (attribution to Cleanor Labs). |
|
|
