Steam Capsule Validator & Previewer

One master image → ZIP of Steamworks-sized PNGs, illustrative preview sheet, policy reminders, and a single-size inspector with safe-area overlays.

  1. Upload high-resolution PNG, JPG, or WebP key art.
  2. Download a ZIP of all required sizes, or open the Inspector tab for one preset with safe-zone overlays and reports.
  3. Use the preview sheet to sanity-check how header, row, library, and tile formats read at a glance.

Exports use center-cropped cover scaling (like a unified resize pipeline). Safe margins are percentage-based per preset. Contrast compares average luminance between an edge band and central ROI; “busy” uses pixel variance as a coarse complexity signal. Policy bullets summarize common Steamworks expectations but are not legal advice — always read current partner rules.

One high-resolution key image is used to generate all Steamworks-oriented sizes (center crop, cover fill). Official dimensions are documented in Steam store assets.

Upload an image to begin.
Does this upload images to your servers?
No. Images are processed with Canvas on your device and are not uploaded.
Are these official Steam specifications?
Presets follow Steamworks partner documentation dimensions (e.g. header, small, main, vertical, library hero, portrait). Always verify the latest store asset requirements before publishing.
What is in the ZIP?
PNG files at each preset resolution (center-cropped “cover” from your master), plus a README.txt with links and notes. Use the Inspector tab for safe-zone overlays and heuristics reports.
Can I get a PDF report?
From the Inspector tab, download HTML and use your browser Print dialog to save as PDF, or export JSON.