Getting Started
Supported image formats
Which formats you can upload and which you can export, and what to know about each.
Upload formats
| Format | Notes |
|---|---|
| PNG | Recommended. Supports transparency input. |
| JPG / JPEG | Standard. No transparency in source. |
| WebP | Lossy and lossless variants both accepted. |
| AVIF | Modern, compact. Good for detailed photos. |
| HEIC | iPhone/iPad photos. Converted automatically via WASM. |
Animated variants (animated GIF, animated WebP) are accepted — only the first frame is processed.
Export formats
PNG — Recommended for transparency
PNG with true straight-alpha transparency. Every pixel's RGB value is preserved exactly, even at zero opacity. NSS automatically verifies the exported file has real alpha before delivering the download.
Best for: Photoshop, Figma, Canva, presentations, anywhere you need a transparent image.
WebP
Lossy WebP with transparency. Smaller file sizes than PNG with excellent quality at high settings. Widely supported by modern browsers, Figma, and most design tools.
Best for: web use, when file size matters and transparency is needed.
AVIF
Highly compressed modern format with transparency support. Can be half the size of PNG at comparable quality. Supported in Chrome, Edge, Firefox, and Safari 16.4+. Photoshop support varies by version.
Best for: web optimisation, when you control the publishing pipeline.
JPG (with background)
JPEG does not support transparency. When you export as JPG, NSS composites your cut-out image onto your chosen preview background (or white by default). Good for sharing on platforms that don't support transparent images.
Best for: social media, email, anywhere transparency isn't needed and file size matters.
Choosing the right export format
| Use case | Recommended format |
|---|---|
| Photoshop / Affinity | PNG |
| Figma / Sketch | PNG or WebP |
| Web (transparent) | WebP or AVIF |
| Social media | JPG or WebP |
| Print production | PNG |
Alpha channel notes
PNG and WebP exports from NSS always use straight alpha (also called unassociated alpha or un-premultiplied alpha). This is the correct format for compositing in professional tools. If you've had issues with other tools producing black-background PNGs in Photoshop, see Why does my export show black in Photoshop?.