Should AI images be PNG, JPEG or WebP?

Choose by destination

• Choose PNG for transparent assets, logos and files that will be edited again.
• Choose WebP for website images when the destination supports it and you want a compact file; it can also preserve transparency.
• Choose JPEG for opaque photos where a smaller file matters and transparency is not needed.
• Keep an original PNG when an asset will pass through several design or editing steps.

TokenRex image model formats

• GPT Image 2.5 Flare and Sunburst expose PNG, JPEG and WebP; transparent output requires PNG or WebP.
• GPT Image 2 and GPT Image 1 Mini expose PNG, JPEG and WebP but not the transparent background control.
• Gemini image models do not accept OpenAI output_format controls through TokenRex. Their available formats are listed on each model page.

Avoid format mistakes

• Do not convert a transparent image to JPEG; the transparent area will be filled with a solid colour.
• Do not compress your only master file aggressively. Export a separate delivery copy for the website.
• Measure the result in the place it will appear, especially for text, sharp product edges and brand colours.

Sources

• OpenAI Images API reference

Example

curl https://tokenrex.ai/api/public/v1/images/generations \
  -H "Authorization: Bearer $TOKENREX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-image-2.5-flare","prompt":"Simple blue app icon","background":"transparent","output_format":"webp"}'

Questions

Is WebP always better than PNG?

No. WebP is often compact for websites, while PNG remains a common choice for editing and compatibility.

Why does TokenRex reject transparent JPEG?

JPEG cannot store transparent pixels, so the request would not produce the requested result.