FastStone Image Viewer

FastStone Image Viewer is a free image browser, viewer, converter and light editor for Windows. It opens almost any bitmap a home user is likely to own - JPEG, PNG, GIF, BMP, TIFF, WebP, AVIF, JXL, HEIC and a long list of camera RAW formats - and it does so from a single, extremely responsive window. The first screen is a folder tree with a thumbnail grid, the second is a full-screen canvas that hides every control until the mouse reaches an edge, and the third is a compact editor with crop, straighten, resize, colour adjust, red-eye removal, healing brush, text and watermark tools. Batch conversion, batch renaming, a lossless JPEG rotate, a slideshow builder, a screen capture module and TWAIN scanning are included, so the program covers the whole path from camera card to archived file without a second application.

What it does

The browser pane indexes a folder and shows thumbnails with optional EXIF overlays, star ratings, colour labels and tags. Double-clicking a thumbnail opens the full-screen viewer, where the mouse wheel zooms, the left and right edges turn pages and a click-drag moves the image. From there the editor opens with the E key or the toolbar, and every edit is applied to a copy you choose to save, overwrite or export. The batch convert dialog accepts a whole selection and can resize, rotate, adjust colour depth, add watermarks, rename with a template and convert format in one pass. The scanner and capture modules feed straight into the same editor.

The workflow

Import a card into a dated folder, sort by capture time, then cull with the rating keys until only the keepers carry stars. Open the keepers full screen and use the crop and straighten tools first, because geometry changes are the ones that matter most; colour, sharpening and noise reduction come afterwards. When the same treatment has to be repeated, copy the edit settings and paste them onto the remaining selection, or send the whole set through batch convert with a resize rule and an output folder. Renaming with a date and sequence template turns a chaotic import into a sortable archive.

Practical settings and limits

Set the startup folder to the import directory and enable the thumbnail cache so that revisiting a large folder stays instant. The editor works on 8-bit channels and saves through a copy-or-overwrite prompt; there is no layer stack and no adjustment history that survives a save, so complex retouching belongs elsewhere. Colour management is limited to reading embedded profiles rather than soft-proofing, TIFF and PNG output stays at 8 bits per channel, and the batch rename counter follows the selection order rather than the filename order. Check the numbering on a copy before running a rename over a finished archive, and keep the original files until the batch output has been reviewed.

Who should choose something else

Photographers who need non-destructive editing, layer masks, 16-bit output or soft proofing will want a dedicated RAW developer or a layer-based editor. Users who only look at occasional screenshots can stay with the built-in Windows viewer, and anyone who needs a colour-managed catalogue with keyword databases and virtual copies will prefer a digital asset manager. FastStone Image Viewer is at its best as the fast front end of a Windows photo workflow: browse, cull, crop, batch and archive, then hand the few files that need real retouching to a heavier tool.