CropDen: image sizes and AI image tools

social-media-image-sizes

Image sizes for 14 platforms: 55 sizes with safe zones, upload limits and minimum sizes, plus specs for 6 passport and visa photos. As JSON, an npm package, an agent skill and an MCP server. Data under CC BY 4.0.

Website · JSON · 中文说明

Most size lists stop at width × height. When you crop, you also need to know what the app puts on top of your image: the profile picture over a YouTube banner, the caption bar at the bottom of a Story, the 3:4 profile grid that trims a 4:5 Instagram post. This dataset has those areas in pixels.

Quick look

One size per row. Each group has more sizes in the data.

Passport photos (make one on CropDen):

All sizes and their zones are in data/social-media-image-sizes.json. To crop an image to any of them in your browser, follow the link in the last column.

Use it

npm

npm install social-media-image-sizes

import { getSize, groups } from 'social-media-image-sizes';
const post = getSize('instagram-post/portrait-34');// { width: 1080, height: 1440, ratio: '3:4', exact: true, ... }
const youtube = groups.filter((g) => g.platform === 'YouTube');

CommonJS works too: const { getSize } = require('social-media-image-sizes').

JSON over HTTP

const res = await fetch('https://cropden.com/data/social-media-image-sizes.json');const { groups, passportPhotos } = await res.json();

The endpoint allows cross-origin requests and is cached for an hour.

Use it with AI agents

Skill: make images in the right size

skills/social-media-image-sizes is an Agent Skill for Claude Code, Codex, Cursor and other agents that read SKILL.md. Ask "turn this photo into a YouTube banner" or "what size is an Instagram story?". It picks the size, crops the image on your machine with sharp, keeps the file under the upload limit, and draws a preview with the covered areas in red.

npx skills add geektao1024/social-media-image-sizes

Or copy the folder into ~/.claude/skills/ (Claude Code) or your agent's skills folder.

MCP server: sizes plus AI image tools

CropDen runs a remote MCP server at https://cropden.com/mcp (Streamable HTTP).

Claude Code:

claude mcp add --transport http cropden https://cropden.com/mcp \  --header "Authorization: Bearer YOUR_CROPDEN_API_KEY"

Other clients: add https://cropden.com/mcp as a Streamable HTTP server with the same header. Get a key at cropden.com under Settings → API keys. The AI tools use the same credits as the website, and a failed run is refunded. Without a key, only get_image_sizes works.

What's in an entry

Each group also has formats, facts (video length and similar), verified and a url to crop on CropDen. Passport photos add print size in millimetres and head and eye-line ranges as fractions of the photo height.

How the numbers are checked

• Platform help pages come first. Where a platform publishes nothing (Instagram profile pictures, for example), we use the size current guides agree on.
• Zones with measured: true were measured in the apps. Apps move their buttons around, so treat those as guides.
• verified is the month a group was last checked. Source links for every group are coming in 0.2.0.
• Found a size that's out of date? Open an issue with a link to the source.

If you only want values the platforms document themselves, use The Social Specification, which marks everything else as not documented. This dataset is made for cropping, so it fills those gaps with practical sizes and safe zones.

On the website

CropDen does the cropping. Pick a size, see the safe zones over your own image, and export at the exact pixel size and under the upload limit. The crop and resize tools run in your browser. The site also has batch resizing and AI tools: extend, upscale and remove background.

License

• Data (data/, and the same data in index.js and index.cjs): CC BY 4.0. Credit it like this: Image size data by CropDen (https://cropden.com), CC BY 4.0. On a website, the link is enough.
• Code: MIT.

Thanks

SammaPix (MIT) was our starting reference for which platforms and passport photos to cover, and we cross-checked sizes against its data files.

If this saved you a lookup, a star helps other people find it.

Built in public by Geektao (@geektao0319, posts in Chinese).