Pixohub image specs

npx add-mcp 'https://mcp.pixohub.com/mcp'

Datasets

Every record either quotes an official source (with its address and the date we checked it) or comes from a test we ran with our own tools, described in our editorial policy. Each record also links to the Pixohub tool that does the job. The same files are on GitHub, where you can open an issue if a source has changed.

Star image-specs on GitHub

File	Contents	Records	Updated
platform-image-sizes.json	Official image dimensions, upload limits, cropping and safe zones for social, video, marketplace and print placements — each fact with the official page, a word-for-word quote and the date we checked it.	93	2026-11-08
upload-size-limits.json	File-size and dimension limits for uploads: email attachments, government exam and visa forms, avatars and marketplaces, each with its quoted rule and source.	83	2026-11-08
image-formats.json	JPG, PNG, WebP, AVIF, HEIC, SVG and seven more: compression, colour depth, transparency, animation, metadata and support.	13	2026-11-08
conversion-tests.json	Our measurements of format-to-format conversion on a photo and a transparent graphic: output size, SSIM/PSNR, and whether transparency and EXIF survived.	108	2026-10-24
compression-tests.json	Compress-to-size results (10 KB to 5 MB) on 20 phone photos and the Kodak suite: how many landed under the target, median size, resolution kept and SSIM.	23	2026-10-24
pixohub-resize-presets.json	The pixel sizes Pixohub's resize presets produce. Our working values, not official specifications.	143	2026-11-08

Using the data

The files are plain JSON with open CORS, so you can fetch them from a browser or a build script:

const res = await fetch("https://pixohub.com/open-data/platform-image-sizes.json");
const { items } = await res.json();
const story = items.find((i) => i.id === "instagram-story");
console.log(story.facts.map((f) => f.text));

Licence: CC BY 4.0 for our compilation and measurements — credit “Pixohub (pixohub.com)” with a link. Quoted passages belong to their publishers and are included to show where each fact comes from; check the linked page before relying on a limit, because platforms change them.

MCP server

A free Model Context Protocol server over Streamable HTTP. No account or key; read-only; answers cite their source and link to the matching tool.

https://mcp.pixohub.com/mcp

Tools

• get_platform_image_size — Recommended size, aspect ratio, upload limits and safe zones for a placement (“Instagram story”, “Etsy listing”).
• find_upload_size_limit — The official file-size limit for an upload (“Gmail attachment”, “UPSC photo”), with its quote and source.
• recommend_image_format — Which format to use for a photo, screenshot, logo or animation on the web, email, social or print.
• compression_advice — What to expect when compressing to a target size, from our tests on 44 photos.
• conversion_test_result — Our measured result for converting between two formats (e.g. HEIC → JPG).

Add it to your client

Add to Cursor Add to VS Code

The buttons open Cursor or VS Code and ask before adding the server. Or add it by hand:

Claude Code:

claude mcp add --transport http pixohub https://mcp.pixohub.com/mcp

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "pixohub": {
      "url": "https://mcp.pixohub.com/mcp"
    }
  }
}

VS Code (.vscode/mcp.json):

{
  "servers": {
    "pixohub": {
      "type": "http",
      "url": "https://mcp.pixohub.com/mcp"
    }
  }
}

Claude (claude.ai and the desktop app)

1. Open Settings → Connectors and choose Add custom connector.
2. Name it Pixohub, paste https://mcp.pixohub.com/mcp as the URL and choose Add. No sign-in is needed.
3. In a chat, turn Pixohub on from the tools menu, then ask, for example, “What size is a US passport photo?”

ChatGPT and other apps that accept a remote MCP connector URL work the same way: add a custom connector with the address above.

Related tools

Check a live page’s images with the image SEO checker, or use any of the free image, video and PDF tools.