Free Reference

Aspect Ratio Guide

Click any ratio to copy the syntax for your AI art tool.

1:1

Square

Instagram posts, profile pictures, icons

--ar 1:1
4:3

Standard (4:3)

Classic photos, presentations, prints

--ar 4:3
3:2

Classic Photo (3:2)

35mm film, DSLR photos, prints

--ar 3:2
16:9

Widescreen (16:9)

YouTube thumbnails, presentations, desktop wallpapers

--ar 16:9
21:9

Ultra-wide (21:9)

Cinematic, ultrawide monitors, banners

--ar 21:9
2:3

Portrait (2:3)

Portrait photos, book covers, posters

--ar 2:3
3:4

Portrait Standard (3:4)

Portrait orientation, mobile wallpapers

--ar 3:4
9:16

Vertical (9:16)

TikTok, Reels, Stories, mobile full-screen

--ar 9:16

Recommended Resolutions

SDXL

  • 1:1 — 1024×1024
  • 4:3 — 1152×896
  • 3:2 — 1216×832
  • 16:9 — 1344×768
  • 21:9 — 1536×640
  • 2:3 — 832×1216
  • 9:16 — 768×1344

SD 1.5

  • 1:1 — 512×512
  • 4:3 — 576×448
  • 3:2 — 608×416
  • 16:9 — 672×384
  • 2:3 — 416×608
  • 9:16 — 384×672

Flux

  • 1:1 — 1024×1024
  • 4:3 — 1152×896
  • 16:9 — 1344×768
  • 9:16 — 768×1344
  • Supports up to 2048px

ChatGPT Images

  • 1:1 — 1024×1024
  • 3:2 — 1536×1024
  • 2:3 — 1024×1536
  • API: custom sizes in multiples of 16, ratios from 1:3 to 3:1, up to 3840px

Aspect Ratio Tips

Match Your Use Case

Generate at the ratio you need. Cropping after generation wastes good content and may cut important elements.

Upscale After Generation

Generate at native resolution, then upscale. Going too large during generation causes artifacts and duplicated elements.

ChatGPT Images Sizing

In ChatGPT, just name the shape ("wide 16:9 banner"). Through the API, pass a size such as 1536×864. Sides must be multiples of 16, and sizes above 2560×1440 are experimental.