Mac Font Explorer

A gallery and data explorer for every font in the T3 Code / Codex font picker: the 183 font families installed on this Mac, plus SF Pro.

Live site: https://cornishandy.github.io/mac-font-explorer/ Local file: open Mac Font Explorer.html in Chrome. No server is needed, and you can leave the tab open indefinitely.

What it does

• Specimens of every family in its own face, with a weight selector (100–900) and a starred-only compare view.
• About & history for every font: a summary, its history, designer, original design year, and 1–3 source links. Each card also links to its subtype in the Type guide.
• Type guide: 7 categories, 33 subtypes, and 18 style tags, each with a description, history, and links, plus a "Show fonts" filter button.
• Filters: typeface, subtype, style tags (Narrow / condensed, Handwritten, Calligraphic, Rounded, Heavy / black, Typewriter, Textured / chalk, Formal / elegant, and more, matching any or all), tier, English glyph coverage, monospace, installed on this device, year range and year source, cap height, sentence width, and an any-field rule builder.
• Data table sortable on every column. PCA map of measured geometry. Visual explorer with a configurable X, Y, color, and size scatter chart where every field is a dimension.
• Saved views, and sync across computer and phone through a private GitHub Gist (below).
• Phone-friendly: fonts the phone doesn't have are shown as a pre-rendered image of the Mac rendering instead of a misleading fallback font.

Sync your stars and views between devices

1. On your computer, open the page, go to Refine the collection → Sync across devices, and click Create a token with only the "gist" scope. On GitHub, keep only gist checked, set an expiry you're comfortable with, and click Generate.
2. Paste the token and click Connect. The page creates a secret gist named mac-font-explorer-sync.json in your account, or finds the existing one, and merges in everything saved locally.
3. Click Phone setup link. That copies a link to the live site with the token in the #fragment. AirDrop or message it to yourself and open it on the phone once. The phone stores the token and removes it from the address bar.
4. From then on, stars, saved views, and the weight setting sync automatically: on load, a moment after each change, and when you switch back to the tab. Edits on two devices merge per item.

Export backup / Import backup saves and merges a JSON file if you'd rather not use GitHub. Disconnect forgets the token on that device. Revoke the token at https://github.com/settings/tokens.

Project layout

Path	What it is
Mac Font Explorer.html, index.html	Built single-file pages (identical). Don't edit these directly.
index.template.html, styles.css, app.js, fonts.js	Page source
font-data.js	Built dataset (window.FONT_DATA)
specimens/	183 PNG specimens for devices that don't have a font
data/metrics.json	CoreText measurements (16 pt, regular face)
data/wikidata-years-raw.json	Wikidata typeface inception dates
research/descriptions-*.json	Per-font summary, history, classification, tags, and verified links
research/taxonomy.json	Category, subtype, and tag write-ups
research/AGENT_BRIEF.md	The research brief (taxonomy, tag list, sourcing rules)
tools/	Measurement, specimen, data, and page build scripts
docs/DECISIONS.md	Decisions and their rationale
docs/SESSION_HANDOFF.md	History, the old-thread diagnosis, and a resume prompt

Rebuild

cd ~/Documents/ChatGPT/mac-font-explorer
swift tools/generate-font-metrics.swift > data/metrics.json   # only if installed fonts changed
swift tools/render-specimens.swift                            # only if installed fonts changed
python3 tools/build-data.py                                   # research + metrics → font-data.js
python3 tools/build-standalone.py                             # → Mac Font Explorer.html and index.html

Publish with git add -A && git commit -m "…" && git push. GitHub Pages redeploys in about a minute.

Status

• Gallery, weights, stars, compare
• Categories, subtypes, tiers, years, measurements, sort and filter everything
• PCA map, visual explorer, saved views
• Single-file page that works from file://
• Popularity removed
• Style-tag filter (narrow/condensed, handwritten, …)
• Per-font and per-subtype descriptions, history, and links
• Cross-device sync (GitHub Gist) with export and import fallback
• Image specimens for devices without the font
• Docs: README, decisions, handoff
• GitHub repo and Pages: https://github.com/cornishandy/mac-font-explorer
• T3 Code project on this folder, with the continuation thread renamed "Mac Font Explorer"
• First real Gist sync on the computer and both phones (confirmed by the user on 2026-09-26)