PSB to ICO Converter

PSB (Photoshop Big) is Adobe Photoshop's large-document format, created to overcome the 2GB file size and 30,000-pixel-per-side limits of the standard PSD format. PSB supports files up to 300,000 pixels per side and several times larger in file size, preserving the same layers, masks, channels, and editing data as PSD. It's used almost exclusively for very large, professional design or production files such as billboard art, film compositing, and high-resolution print work.

PSB files open natively in Adobe Photoshop, which automatically switches to the PSB format once a document exceeds PSD's size limits. They can also be opened by other Adobe Creative Cloud applications and select third-party editors with PSB support, such as Affinity Photo, though broad cross-platform support is limited compared to PSD.

The ICO format is an image container specifically designed for Microsoft Windows to store icons for executable files, folders, and applications. Introduced with Windows 1.0, it can encapsulate multiple raster images of varying dimensions and color depths (specifically BMP or PNG frames) within a single file to support dynamic scaling across different display resolutions. The structure comprises an ICONDIR header referencing one or more ICONDIRENTRY directory entries, allowing the operating system to select the appropriate 16x16, 32x32, or 48x48 pixel resource based on the current UI scaling settings.

ICO files are natively supported by the Microsoft Windows operating system, which automatically renders them in the File Explorer and taskbar. On macOS, Apple Preview handles the format natively. For editing or detailed inspection of the contained bitmap layers, raster graphics editors such as GIMP, Adobe Photoshop (via plugin), or Paint.NET are required. Web browsers also natively render ICO files when they are designated as favicons.