YouTube Thumbnail Sizes & Dimensions

Complete reference for all YouTube thumbnail quality tiers, dimensions, aspect ratios, and typical file sizes.

Overview

YouTube automatically generates multiple thumbnail variants for every uploaded video. These variants follow a consistent naming and sizing convention. The table below documents each tier.

Key point: Availability varies. Default through Standard exist for virtually all videos. Max Resolution (1280×720) only exists for videos uploaded in HD (720p or higher) after YouTube introduced HD thumbnail support (~2012).

Thumbnail Quality Tiers

Quality Dimensions (W × H) Aspect Ratio Typical File Size Availability URL Suffix
Default 120 × 90 4:3 ~2–5 KB Always /default.jpg
Medium (mqdefault) 320 × 180 16:9 ~10–20 KB Always /mqdefault.jpg
High (hqdefault) 480 × 360 4:3 ~20–50 KB Always /hqdefault.jpg
Standard (sddefault) 640 × 480 4:3 ~30–80 KB Always /sddefault.jpg
Max Resolution (maxresdefault) 1280 × 720 16:9 ~100–300 KB HD uploads only /maxresdefault.jpg

Aspect Ratios Explained

YouTube uses two aspect ratios across thumbnail tiers:

  • 16:9 (widescreen) — Medium (320×180) and Max Resolution (1280×720). Matches the video player aspect ratio.
  • 4:3 (standard) — Default (120×90), High (480×360), Standard (640×480). Legacy from YouTube's early 4:3 player era.

When designing custom thumbnails for upload, YouTube recommends 1280×720 (16:9) as the ideal upload size. The platform will downscale to generate the other tiers automatically.

Direct Thumbnail URL Patterns

Each thumbnail is accessible at a predictable URL:

https://img.youtube.com/vi/{VIDEO_ID}/{QUALITY_SUFFIX}.jpg

Where {QUALITY_SUFFIX} is one of:

  • default — 120×90
  • mqdefault — 320×180 (Medium Quality)
  • hqdefault — 480×360 (High Quality)
  • sddefault — 640×480 (Standard Definition)
  • maxresdefault — 1280×720 (Maximum Resolution)

Example for video dQw4w9WgXcQ:

https://img.youtube.com/vi/dQw4w9WgXcQ/maxresdefault.jpg
https://img.youtube.com/vi/dQw4w9WgXcQ/hqdefault.jpg
https://img.youtube.com/vi/dQw4w9WgXcQ/mqdefault.jpg
https://img.youtube.com/vi/dQw4w9WgXcQ/sddefault.jpg
https://img.youtube.com/vi/dQw4w9WgXcQ/default.jpg

Custom Thumbnail Upload Requirements

If you're a creator uploading custom thumbnails, YouTube's official requirements:

  • Resolution: 1280 × 720 (minimum 640×360)
  • Aspect ratio: 16:9
  • File size: Under 2 MB
  • Format: JPG, GIF, BMP, or PNG (no animated GIFs)
  • Safe area: Keep critical content within center 80% to avoid cropping on different devices

Why Some Qualities Are Missing

  • Video uploaded before HD support (~2012) — No maxresdefault generated
  • Original upload was low quality — YouTube doesn't upscale
  • Processing errors — Rare, but sometimes a specific tier fails to generate
  • Private/unlisted videos — Thumbnails may not be publicly accessible

Our downloader tool only displays qualities that actually exist for the requested video.