Free image resizer

YouTube thumbnail resizer

Crop an image for a video thumbnail (16:9), a Shorts thumbnail (9:16), your channel banner (2560 × 1440) or profile picture. In your browser.

  • Free
  • No sign-up
  • Runs in your browser
Platform
Size

Small enough for YouTube's 2 MB limit when uploading from a phone; from a computer it takes up to 50 MB.

Source: the platform's help page

Drop an image here

Resized in your browser and never uploaded.

How it works

  1. 1

    Pick the platform and what the image is for: a post, a Story, a banner or a thumbnail.

  2. 2

    Drop your image and drag it to choose what stays in the frame, or fit it whole on a background.

  3. 3

    Download it at the exact size, as JPG or PNG.

Image sizes per platform

The sizes the resizer makes, each with where it comes from: the platform's own page wherever it publishes one.

PlatformForSizeShapeSource
YouTubeThumbnail (HD)1280 × 72016:9the platform's help page
YouTubeThumbnail (4K)3840 × 216016:9the platform's help page
YouTubeShorts thumbnail1080 × 19209:16the platform's help page
YouTubeProfile banner2560 × 144016:9the platform's help page
YouTubeProfile picture800 × 8001:1an industry guide

Checked 6 November 2026.

Tips

  • Tip 1For Instagram's feed, 4:5 portrait (1080 × 1350) takes the most room on a phone.
  • Tip 2Keep text and faces away from the edges of covers and banners: phones and computers crop them differently.
  • Tip 3Use PNG for text and logos, JPG for photos.

Use it from an AI app

ChatGPT, Claude and other AI apps can run this too, through the free API or the free MCP server. No account or key needed.

API

curl "https://superbridger.com/api/tools/image-sizes?platform=instagram"

JSON in, JSON out, open to any site (CORS). The OpenAPI description lists every endpoint. OpenAPI

MCP server

https://superbridger.com/api/tools/mcp
→ get_image_sizes

Add https://superbridger.com/api/tools/mcp as a custom connector in Claude, or as an app in ChatGPT. No sign-in.

Reference for AI apps (Markdown)

FAQ

Questions

What size is a YouTube thumbnail?

16:9, at least 640 pixels wide, as large as 3840 × 2160. Small enough for YouTube's 2 MB limit when uploading from a phone; from a computer it takes up to 50 MB.

Can a Short have its own thumbnail?

Yes: 9:16, such as 1080 × 1920. YouTube takes Shorts thumbnails in YouTube Studio on a computer, from a verified account.

What size is a YouTube banner?

2560 × 1440 (at least 2048 × 1152, up to 6 MB). Only the middle 1235 × 338 shows on every device.

Is my image uploaded?

No. It's resized in your browser and saved straight to your device.

What happens to the parts that don't fit?

They're cropped. Drag the image to choose which part stays, and zoom in if you like. Or choose Fit to keep the whole image on a background colour.

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Superbridger runs these checks before every post, then publishes to every platform at once.