What “processed locally” really means.
Local processing is a narrow, useful claim: the code that reads and transforms selected document contents runs on your device. It reduces document exposure, but it should not be confused with anonymity, offline operation, or a promise that no network request exists.
The document path
When you choose a file, the browser grants the page access to that selected file. Gluecut's JavaScript libraries parse it in the browser's memory, create previews, apply the chosen order, and generate a downloadable result. Gluecut does not operate a document-conversion API that receives the source file. Saved workspaces use IndexedDB inside your browser profile rather than a Gluecut account.
This differs from a conventional upload service, where the browser transfers the document to a remote server and waits for that server to return a result. Removing that transfer reduces the number of systems entrusted with document contents and avoids a remote retention copy created solely for conversion.
The website still uses a network
Your browser must normally request the Gluecut page, scripts, styles, and other web resources. Hosting infrastructure can receive ordinary request data such as an IP address, user agent, requested path, and timestamp. Gluecut also uses analytics and advertising technology under the Privacy Policy. Those systems are configured and described separately from document processing; selected document contents, filenames, workspace names, and entered text are not intended to be sent as analytics or advertising data.
How to verify the boundary yourself
Modern desktop browsers include developer tools. Open the Network panel, load the page, clear the log, then select a harmless test document containing no sensitive information. Merge it while watching requests. A local workflow should not show the test document being posted to a conversion endpoint. You may still see page, analytics, consent, or advertising requests consistent with the privacy disclosure.
You can also disconnect the network after the application has fully loaded and try a small test merge. Browser caches and external resources affect this experiment, so it is supporting evidence rather than a complete security audit. Technically experienced users can inspect the public source repository and built request behavior.
Threats local processing does not solve
A compromised device, malicious browser extension, shared browser profile, screen capture, clipboard monitor, or unauthorized person at the keyboard can still expose a document. Files saved to Downloads or IndexedDB remain subject to device access, backups, synchronization, and retention settings. Local processing also does not repair unsafe source files or establish that a result is legally compliant.
A cautious workflow for sensitive material
Use a maintained browser and trusted device. Disable unnecessary extensions or use a clean browser profile. Confirm that the address is https://gluecut.app. Work with copies, avoid public or managed devices you do not trust, inspect the result, remove saved workspaces when finished, and handle downloaded files according to your organization's policy.
For classified, regulated, privileged, or high-impact material, local browser processing may still be outside an organization's approved tool list. Follow the stricter rule and consult the responsible security or privacy team. Privacy is a system property, not a label attached to one processing step.