SageThumbs Formats Guide: PSD, RAW, AI/EPS/PDF and More

SageThumbs renders its previews through the GFL graphics library, which covers 162 image formats. That breadth is the reason a single small extension can preview everything from Photoshop documents to decades-old game textures inside Windows Explorer. This hub groups our per-format guides so you can check how a specific file type behaves, what it needs, and where its limits are before you rely on it in a working folder.

One dependency matters more than any other: vector and PostScript-based formats such as AI, EPS and PDF are not rendered by GFL alone. They need AFPL GhostScript 8.54 installed alongside SageThumbs, in the matching 32-bit or 64-bit build. If those three formats show generic icons while everything else previews correctly, GhostScript is the first thing to check.

Format guides

PSD Thumbnails in Windows Explorer: The Complete Guide

Our flagship guide to Photoshop PSD previews: how SageThumbs renders them, which PSD features affect the preview, and how to get reliable results.

SageThumbs Supported Formats: The Full 162-Format List Explained

The complete supported-format picture in one place, explaining what the 162-format GFL list means in practice and how to check a specific extension.

Camera RAW Thumbnails in Explorer: CR2, NEF, ARW, DNG and More

How camera RAW previews work in Explorer, which RAW families SageThumbs and Windows each handle, and why results vary by camera model.

AI, EPS and PDF Thumbnails: Why They Need GhostScript 8.54

The dedicated guide to the three GhostScript-dependent formats, covering why they are different and what a correct installation looks like.

XCF Thumbnails in Windows Explorer (GIMP Files)

How GIMP’s native XCF files get Explorer thumbnails, and what to expect from layered or very large images.

PSP Thumbnails in Windows Explorer (PaintShop Pro Files)

Preview support for PaintShop Pro’s PSP format, a legacy format that modern Windows does not handle natively.

DDS Thumbnails in Windows Explorer (Game Textures)

DDS texture previews for game development and modding folders, where Windows shows nothing useful by default.

TGA Thumbnails in Windows Explorer

Targa TGA previews explained, another graphics-workhorse format that Explorer ignores without an extension like SageThumbs.

ICO and CUR Thumbnails in Windows Explorer

How icon and cursor files preview in Explorer, and the quirks of formats that are themselves made of images.

Formats SageThumbs does not support

Being clear about the gaps matters as much as the supported list. The classic SageThumbs release does not preview the following formats, and no setting changes that: WebP, SVG, HEIC, AVIF, INDD (Adobe InDesign) and CR3 (Canon RAW). WebP and HEIC are better served by the codecs and extensions Microsoft and the format owners publish for Windows, SVG by a dedicated SVG shell extension, and CR3 by Canon’s or Microsoft’s current RAW support. If one of these formats is central to your workflow, the comparisons hub looks at alternative tools that cover some of them. For everything on the supported list, the download page has the installer and the matching GhostScript build.

How Explorer decides what you see

Windows Explorer asks registered thumbnail providers to render a preview the first time you view a file, then stores the result in its thumbnail cache so the folder draws instantly next time. SageThumbs registers itself as the provider for the formats on its list, which is why installation changes folders you have already opened: the next visit re-renders what the cache could not previously produce. It also explains two behaviours readers often mistake for faults. Previews appear progressively in very large folders, because each file is rendered on demand, and a file that is still being written by another program, such as a PSD mid-save, may show a generic icon until you refresh the view.

Preview quality follows the size of the image data the source file carries. A small or heavily compressed embedded preview cannot become sharper just because Explorer displays it larger, and some formats only store a low-resolution rendition. The per-format guides above flag these cases individually, so check the guide for your format before assuming the extension is at fault. Where a format stores a full-resolution image, SageThumbs can use it, and the difference is obvious in the large-icons and extra-large-icons views.