YouTube Thumbnail URL Format

Every public YouTube video exposes its thumbnails at predictable addresses. You do not need an API key, OAuth, or scraping. This page lists every known thumbnail file, when each one exists, and how to use them in code. Bookmark it; nothing here requires our tool, though the thumbnail grabber does it in one click.

The Base URL Pattern

https://img.youtube.com/vi/<VIDEO_ID>/<FILE>.jpg
https://i.ytimg.com/vi/<VIDEO_ID>/<FILE>.jpg   (same files, CDN host)

The VIDEO_ID is the 11-character code in any YouTube link: after v= in a watch URL, after /shorts/ in a Shorts URL, or the path of a youtu.be link.

Every Thumbnail File YouTube Stores

The letterboxed 4:3 files (hqdefault, sddefault, 0.jpg) include black bars above and below the 16:9 image. If you need clean 16:9 with guaranteed availability, use mqdefault.jpg.

WebP Versions

YouTube serves smaller WebP files from the vi_webp path:

https://i.ytimg.com/vi_webp/<VIDEO_ID>/hqdefault.webp
https://i.ytimg.com/vi_webp/<VIDEO_ID>/mqdefault.webp

Live Stream Thumbnails

Active live streams refresh their thumbnail at a _live suffix:

https://i.ytimg.com/vi/<VIDEO_ID>/hqdefault_live.jpg

The maxresdefault Trap (and the Right Fallback Chain)

The most common bug in thumbnail code: assuming maxresdefault.jpg always exists. It does not. For videos uploaded below 720p without a custom thumbnail, that URL returns a 404 (or a gray 120x90 placeholder via some CDN edges). Use this fallback order: maxresdefault, then sddefault, then hqdefault, which always exists.

JavaScript

function getThumbnail(videoId) {
  const files = ['maxresdefault', 'sddefault', 'hqdefault'];
  return new Promise((resolve) => {
    const tryNext = (i) => {
      const img = new Image();
      const url = `https://i.ytimg.com/vi/${videoId}/${files[i]}.jpg`;
      img.onload = () => (img.naturalWidth > 120 || i === files.length - 1) ? resolve(url) : tryNext(i + 1);
      img.onerror = () => tryNext(i + 1);
      img.src = url;
    };
    tryNext(0);
  });
}

Python

import requests

def get_thumbnail(video_id: str) -> str:
    for f in ("maxresdefault", "sddefault", "hqdefault"):
        url = f"https://i.ytimg.com/vi/{video_id}/{f}.jpg"
        if requests.head(url, timeout=5).status_code == 200:
            return url
    return f"https://i.ytimg.com/vi/{video_id}/hqdefault.jpg"

Extracting the Video ID

const ID_RE = /(?:v=|\/(?:shorts|embed|live|v)\/|youtu\.be\/)([0-9A-Za-z_-]{11})/;
const id = (url.match(ID_RE) || [])[1];

Usage Notes

• Thumbnail URLs are public and need no authentication, but the images themselves remain the creator's copyright. Credit creators when you republish.
• The oEmbed endpoint (https://www.youtube.com/oembed?url=...&format=json) also returns a thumbnail_url field if you prefer an API-style call.
• Hotlinking from i.ytimg.com works and is how YouTube itself serves these files, but cache them on your side for production use.

Prefer not to write code at all? Paste any link into the YouTube thumbnail grabber and download every size in one click.