Social Media Image Sizes

Setup

cd <skill-dir>
npm install

Check an image

node scripts/check.js photo.jpg

node scripts/resize.js

node scripts/check.js photo.jpg --platform instagram
node scripts/check.js photo.jpg --filter perfect
node scripts/check.js photo.jpg --filter usable

instagram

facebook

twitter

linkedin

tiktok

youtube

pinterest

snapchat

threads

Resize an image

node scripts/resize.js photo.jpg "Instagram Portrait Post"
# → photo-instagram-portrait-post.jpg  (1080×1350 px)

node scripts/resize.js photo.jpg "YouTube Custom Thumbnail"
# → photo-youtube-custom-thumbnail.jpg  (1280×720 px)

--fit contain

node scripts/resize.js photo.jpg "LinkedIn Background Photo" --fit contain --bg f0f0f0
node scripts/resize.js photo.jpg "Instagram Portrait Post" --out ./exports/ig.jpg

node scripts/resize.js photo.jpg --list

Workflow

1. Run

   check.js

   to see what a given image already matches
2. Copy the suggested

   resize.js

   command from the output
3. Run it — the output file is saved alongside the original by default

Gotchas

• Sharp requires a native binary. On first

  npm install

  , it downloads a prebuilt binary for your platform. If install fails behind a proxy, set

  SHARP_IGNORE_GLOBAL_LIBVIPS=1

  and retry.
• All slides in an Instagram carousel must share the same aspect ratio. The first image sets the ratio for the whole carousel — check all slides, not just the first.
• Facebook cover photo has two safe zones. Desktop shows 820×312; mobile crops to 640×360. Keep key content in the center 640×312.
• YouTube banner safe area is much smaller than the file. The spec is 2560×1440 but only the center 1546×423 is guaranteed visible on all devices. check.js flags the full size; keep critical content in the safe area.

• --fit cover

  center-crops. If the subject isn't centered, use

  --out

  to save, then manually crop, or use an image editor before running resize.

References

• references/instagram.md

  — profile, feed, stories, reels, carousel, ads

• references/facebook.md

  — profile, cover, feed, stories, events, ads

• references/x-twitter.md

  — profile, header, posts, ads

• references/linkedin.md

  — profile, cover, feed, articles, ads

• references/tiktok.md

  — profile, videos, ads

• references/youtube.md

  — channel art, videos, thumbnails, shorts, ads

• references/pinterest.md

  — profile, pins, idea pins, ads

• references/snapchat.md

  — snaps, spotlight, stories, ads, filters

• references/threads.md

  — profile, posts

• references/best-practices.md

  — format, compression, safe zones, accessibility

AGENTS.md