SageThumbs 2K 4.0.0: Screenshot Pinning, Multilingual OCR and OneDrive Thumbnail Fix

What SageThumbs 2K is​

SageThumbs 2K is a rebuild of the old SageThumbs shell extension, not a patch of it. The project's repository describes it as a Windows 11 shell extension written in Rust that gives Explorer thumbnails for file types Windows can't show, such as camera RAW, PSD, HEIC/AVIF, video, ebooks, comics and CAD. The repository's README says the original SageThumbs ran from 2004 to 2017. It says the new project is a clean-room rewrite that reuses no GFL code from the original.

The developer says the thumbnail provider runs out-of-process in Explorer's isolated dllhost surrogate. It uses several decoding tiers, including Windows' own codecs and a sandboxed ImageMagick child process. The goal is that a corrupt file can't take Explorer down with it. Those are the developer's design claims, not something independently tested here.

A compatibility caveat: Neowin's listing says the tool supports Windows 10 and Windows 11. The project's own README lists the system requirement as Windows 11, 64-bit, with native x64 and ARM64 builds. Windows 10 users should treat support as unconfirmed.

What's new in 4.0.0​

The release was uploaded to the project's GitHub page on 6 November, according to the release listing. Neowin posted it on 7 November. The headline additions:

• Pin a screenshot on top. The screenshot toolbar gains a pin button. It closes the capture and keeps the selection, annotations included, on screen as a small always-on-top window. You can drag it and zoom with the mouse wheel. Ctrl+C copies it, Ctrl+S saves it, and Esc or a double-click closes it. Several pins can stay open at once.
• Screenshots copy as HDR. This only applies if you've chosen PNG HDR or JPEG XR HDR as the save format. Copy then puts two versions on the clipboard. One is the ordinary bitmap every program accepts. The other is a 16-bit PNG HDR that browsers, Discord and other PNG-pasting programs use, so colour and brightness survive without saving a file first.
• Folder icons from folder.ico. Turn on the "Use folder.ico icons" option on the Appearance page and it appears in the folder right-click menu. Choosing it makes that folder and every folder inside take the icon from its own folder.ico. A separate "Folder icons by name…" option assigns icons by folder name, with * and ? wildcards. The developer's example maps node_modules to an npm icon. The project says other desktop.ini contents are kept. The option is off by default, and the README says it writes a desktop.ini in folders it processes.
• OCR in other languages. Settings ▸ Screenshots ▸ OCR language now sets the language for screenshot OCR, the right-click Copy text action, searchable-PDF creation and Quick preview's copy-text. The list comes from OCR packs already installed in Windows, and the default follows your Windows profile languages. The st2k ocr --lang and st2k pdf --searchable --lang commands override it. If the language isn't installed, the app won't silently use another one. It tells you where to add it.
• Portable copy can start with Windows. A "Start with Windows, in the tray" option on the Screenshots page starts the screenshot hotkey and Quick preview at sign-in. Unticking it removes the sign-in task. Thumbnailing itself doesn't need the tray helper running.

New thumbnail formats, with limits​

Three formats gain thumbnails, and each has caveats:

• Atari ST NEOchrome .neo: only low-resolution files are decoded. Medium and high resolution files are not read.
• PhotoCraft .pcraft: the thumbnail is the flattened preview PhotoCraft saves inside the file. The layers are not composited.
• Resolume DXV3 .mov: clips used to show the plain icon because Windows has no decoder for them. SageThumbs 2K now decodes the first frame itself, in its own short-lived process, for the DXT1 and DXT5 modes, while the YCoCg high-quality modes still show the plain icon.

If your DXV3 clips use the YCoCg modes, expect no change.

Fixes that matter day to day​

• OneDrive thumbnails. OneDrive could put its own thumbnail handler back when sync resumed. Files such as .clip then showed a stock icon until you signed out and back in. SageThumbs now notices within seconds and links itself back in.
• Animated JPEG XL. Quick preview, opened with Space, now plays a .jxl animation frame by frame, as it already did for GIFs, instead of showing a still.
• Updates that need a restart. The README says the updater used to miss its own pending file when another program, such as a browser update, had already queued a delete. It then started a silent update that stalled on the installer's "restart your computer" box. It now says a restart is needed.
• Video preview shape. Video keeps its aspect ratio, with black bars, when you resize the window or toggle full screen.
• Legacy Office files. Old .xls and .pub files with drawing thumbnails are no longer stretched to your screen's shape.
• Screenshot toolbar overlap. On a whole-display capture, the key-bind guide strip no longer paints over the toolbar.
• Tray Exit. It now closes an open Settings window too.
• Interface polish. The About window text and logo fit at every display scaling, and a Settings line fits in Greek at 150% and 200%.
• Format mark sizing. The overlay mark now takes a bigger share of small thumbnails and a smaller share of large ones, so it stays legible without covering big previews.

Installer or portable?​

The 4.0.0 release lists x64 and ARM64 installers and portable ZIPs. On SourceForge the sizes are 15.5 MB and 14.0 MB for the x64 and ARM64 installers. The portable ZIPs are 28.5 MB for x64 and 26.6 MB for ARM64. Neowin's "~25.0 MB" figure doesn't match these. Presumably it refers to a different file, but the sources don't say which.

The README says every file is code-signed by LUNARWERX LLC. It publishes SHA-256 hashes so you can check a download. Right-click the file, open Properties ▸ Digital Signatures, and compare the hash with the one published for your build.

The portable build is the lower-commitment option. Unzip and run, and nothing is installed. Running st2k register, or using Settings ▸ Advanced, turns on Explorer thumbnails and the classic right-click menu for your account. The preview pane, the Details pane and the Windows 11 compact right-click menu still need the installer. They need machine-wide registration.

One filename quirk: SageThumbs2K-Setup-4.0.0-amd64.exe is the x64 installer again, under the name older copies look for. The release notes say to download the plain-named installer.

For a portable copy, the README also describes a manual route. Put a shortcut in shell:startup whose target ends in --screenshot-daemon. Without that argument, the shortcut just opens Settings. The README's description predates the new built-in option, so use the new setting first.

Licensing and trust​

The README says SageThumbs 2K is free for personal use under the PolyForm Noncommercial License 1.0.0. That is source-available rather than OSI open source, even though Neowin and SourceForge label it open source.

The release notes also describe a paid tier:

• Supporter (home use) costs US$2 a month or US$20 a year. It covers Quick preview, the screenshot tool, OCR, settings sync and the MCP server's tools. Each is free for 14 days from first use. Thumbnails, Explorer's preview pane and the rest of the right-click menu stay free.
• Business costs US$5 a month or US$50 a year per computer. It is needed for commercial use. The README says a business copy gets a 7-day evaluation, then 3 days of reminders. After that, thumbnails, previews and the right-click menu stop until a key is entered.

That matters for IT admins. A tool that quietly stops thumbnailing on a work PC is a support ticket waiting to happen. Several headline features in 4.0.0, including the screenshot pinning and OCR, sit behind the Supporter trial.

The README also says the installer registers a classic shell extension via regsvr32 and trusts a self-signed certificate for the Windows 11 modern menu. It says the extension isn't packaged as MSIX because it spawns ImageMagick as a subprocess. Admins who audit shell extensions should know that before deploying. The README adds that a brand-new signed release can still trigger SmartScreen while it builds reputation, and that antivirus scores can vary for fresh binaries.

Bottom line​

For photographers, designers and anyone drowning in RAW, PSD, HEIC or JXL files, 4.0.0 adds real conveniences. The OneDrive fix and the restart-notice fix are the most practical for everyday users. The licensing split and the Windows 11-only requirement are the things to check before you roll it out widely.