A free, open source screenshot tool and screen recorder for Windows. Press Print Screen, select, and the capture is already copied, waiting as a floating thumbnail to annotate, drag or share.
- 01 / INPUTOne key: Print Screen
- 02 / PROCESSAnnotate, cover, record
- 03 / OUTPUTCopied, ready to paste
The problem
Sharing a piece of the screen usually means a chain of small chores: capture, open an editor, crop, mark it up, hide what should not be seen, save, find the file and attach it. Stackshot puts that chain behind one key on Windows: the capture is already on the clipboard and waits as a floating thumbnail, so annotating, covering sensitive data or recording a short video stays one step away.
Watch the demo
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- Press Print Screen and choose one of the seven capture modes.
- Select an area: the capture is copied and waits as a floating thumbnail.
- Annotate it, cover sensitive data or capture a whole scrolling page.
- Record MP4 or GIF with sound, then find any capture later by the text it contains.
Technical decisions
One small executable, nothing else to install
The app is written in C# on the .NET Framework that ships with Windows 10 and 11, with WinForms and WPF, and it compiles with the C# compiler included in Windows through a PowerShell script. The result is a single 2.2 MB executable that runs without admin rights, plus an MSI package for managed installs.
The capture is ready before you decide
Every screenshot is copied to the clipboard as soon as it is taken and appears as a floating thumbnail, while the PNG is written in the background. The area picker redraws only the region that changed, about 1.6 ms per pointer move at 1080p in the project's own measurements.
Text and sensitive data stay on the PC
The text inside captures is read with the OCR built into Windows. It feeds the history search and the detection of ID numbers, IBANs, cards, e-mails and phone numbers, which checks control digits so invoice numbers and amounts are left alone. There are no accounts, cloud services or telemetry.
Recordings that check themselves
Video and GIF rely on FFmpeg, downloaded only the first time you record, after you accept, and verified against a SHA-256 hash kept in the source. The lossless Cine master is decoded after recording and compared frame by frame, and every MP4 export is checked before it is handed over.
Updates that cannot be swapped
An update installed from the app must match the SHA-256 that GitHub reports and carry an RSA-PSS signature made with a key that is never stored in the repository. Releases are compiled by GitHub Actions and published with a checksum and a signed provenance attestation.
Documentation rendered from the real app
The README screenshots, the feature clips and the film are produced by scripts from real app screens over synthetic content. When the interface changes, the media is generated again instead of being retouched by hand.
Limits and data handling
- Windows 10 and 11 only. The interface is in Spanish today; an English translation is planned.
- The executable is not code-signed yet, so SmartScreen warns the first time it runs. Each release publishes a SHA-256 checksum and a provenance attestation to check what you downloaded.
- Sensitive-data detection can miss data. Automatic covering is off by default, and every result should be reviewed before it is shared.
- Text recognition relies on the OCR built into Windows, so its accuracy depends on the system and on the image. The history's text index can be turned off or deleted.
- Recording needs FFmpeg, which is not bundled and is distributed under its own GPL license. Apart from that download, the network is used only for update checks against the GitHub Releases API, which can be turned off.
- Timings such as 1.6 ms per pointer move or about 0.4 s to cover data at 1080p are the project's own measurements, not an independent benchmark.
A verifiable result
The deliverable is a working Windows app, published as an executable and an MSI package on GitHub Releases, with its source under the MIT license and a website that presents it with the full film. No download, adoption or time-saving figures are claimed.
How to check it
- Download Stackshot from its website or from GitHub Releases, compare the SHA-256 checksum and run it without admin rights.
- Press Print Screen, select an area and paste it with Ctrl+V. Open the thumbnail in the editor and try the sensitive-data button on a document with synthetic data.
- Inspect the App repository for capture, OCR, recording and update verification, and each release for its SHA-256 checksum and provenance attestation.
