Datasets:

cleanorlabs
/

developer-reference-datasets

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

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 (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).