heic-to-jpeg-bundle

Self-Evolving Skill: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues.

Turn a folder of HEIC (or any sips-readable) images into a share-ready JPEG bundle: a self-contained gallery page plus an optional password-protected ZIP. Everything runs through macOS sips and zip — no Homebrew, no Python, no ImageMagick.

Why this exists

iPhones shoot HEIC by default. HEIC is poorly supported on Windows and in a lot of appraisal / CRM / dealer / insurance software, so recipients hit a wall: they can see the file but can't open or import it, and free online converters are flaky. Re-encoding to JPEG once, locally, removes that wall for everyone downstream.

When to use

• A recipient says they "can't open" / "can't convert" your photos (HEIC → JPEG).
• You're handing a photo set to a non-technical person or to software that wants JPEG.
• You're prepping images to drop on a static host (see the companion cloudflare-workers-publish skill) and want a gallery + a bulk-download ZIP.

For the full end-to-end playbook (pull from a cloud album → bundle → host unlisted → share via a gist gateway), see the photo-gallery-delivery skill, which orchestrates this one.

Quick start

SKILL_DIR="$(dirname "$(find ~/.claude ~/eon -path '*/heic-to-jpeg-bundle/scripts/make-bundle.sh' 2>/dev/null | head -1)")"

# Gallery + password-protected ZIP that fits the Cloudflare Workers 25 MiB cap:
bash "$SKILL_DIR/make-bundle.sh" \
  --src ~/Pictures/my-photos \
  --title "2023 Corolla Cross — trade-in photos" \
  --zip --password "CorollaCross2023" --zip-cap-mib 25

# Also emit a full-resolution JPEG tier (host its ZIP off a large-file host, not Workers):
bash "$SKILL_DIR/make-bundle.sh" --src ~/Pictures/my-photos --full --zip

Output:

<src>/_bundle/site/index.html        # gallery: thumbnails -> full "view" JPEGs
<src>/_bundle/site/photos/photo-NNN.jpg
<src>/_bundle/site/thumbs/photo-NNN.jpg
<src>/_bundle/site/bundle.zip        # when --zip and it fits the cap
<src>/_bundle/full/photo-NNN.jpg     # when --full (full-res tier)

Deploy the site/ directory to any static host. Tap-through opens the 2048px "view" JPEG, so close-up detail (VIN stickers, odometer, damage) stays legible even if the ZIP tier was downscaled to fit a size cap.

Options

Key facts and gotchas

• sips honors EXIF orientation when it resamples (-Z), so portrait shots come out upright. It ships on every macOS — never reach for ImageMagick/magick for this.
• Static hosts cap file size. Cloudflare Workers Static Assets reject any single file > 25 MiB (hard error: Asset too large). A ZIP of ~120 full-res iPhone JPEGs is ~100–500 MB and will not fit — hence --zip-cap-mib, which downscales the ZIP tier (not the gallery) until it fits. For a true full-resolution bulk download, host that ZIP on a large-file host (R2, a GitHub Release, your own server), not on Workers.
• ZipCrypto, on purpose. --password uses classic ZipCrypto (zip -e), which Windows Explorer, 7-Zip, and macOS Archive Utility all open natively with the password. AES-256 zips are stronger but need 7-Zip on the recipient's end — more friction for a non-technical recipient, so ZipCrypto is the pragmatic default. It's a light access gate, not strong cryptography.
• Password-on-the-gateway model. The gallery page never prints the ZIP password. Put the password only on whatever gateway you share (a gist, an email, a message). Then finding the bare ZIP URL alone won't open it — the gateway is required. See cloudflare-workers-publish for the hosting side.
• JPEGs are already compressed, so the ZIP uses store (-0), not deflate — zipping doesn't shrink them and -0 is faster.
• Filenames with spaces/parentheses (Amazon/iCloud exports) are handled — the script reads sources null-safely and renames outputs to stable photo-NNN.jpg.
• The gallery is emitted as pure ASCII (every non-ASCII char — em-dash, middot, arrows, emoji, and anything in your --title — is folded to a numeric HTML entity like —). ASCII is byte-identical under UTF-8 / Latin-1 / Windows-1252, so the page cannot mojibake even if a host serves text/html with no charset (Cloudflare Workers does exactly that). A build-time guard (iconv -f ASCII) fails the run if any non-ASCII byte survives.
  • Hazard this prevents: never run an in-place perl -pe / sed -i edit that inserts non-ASCII (e.g. \x{2014}, \x{2B07}, an emoji) over a UTF-8 file without the -CSD layer — perl will read the existing multibyte bytes as Latin-1 and re-emit them as UTF-8, silently corrupting them (the tell-tale Wide character in print warning). Each pass re-encodes again. If you must post-edit generated HTML, edit ASCII entities, or use perl -CSD. This skill avoids the pattern entirely by folding to entities once.

Preflight

sips and zip are macOS built-ins; the script fails fast if either is missing. No other dependencies.

Post-Execution Reflection

After running, before closing:

1. Did conversion or the ZIP fail? Fix the step in make-bundle.sh that caused it.
2. Did a host reject a file for size? Confirm --zip-cap-mib matches that host's real cap, and record the cap if it differs from 25 MiB.
3. Did a recipient still struggle to open the ZIP? Note their tool; if AES was needed, document it. Update this SKILL.md only for real, reproduced issues.