Searching a document means reading its contents somewhere. For a privacy-conscious Windows user, the practical question is where that reading happens, what gets stored, and whether the app sends anything away. “Offline” should describe a specific boundary, not promise that a computer or every related service never touches the internet.
Local search keeps the work on your computer
Hannun is an offline Windows file finder. You choose the folders it searches. Search and indexing run locally in the desktop app; it has no app account, ads or telemetry. It does not send your files, extracted text or searches to a search service. Windows file permissions still apply: Hannun cannot make a folder readable if your Windows account cannot open it.
When you turn on search inside files, Hannun reads supported documents and stores extracted text in a local index so later searches can find words inside them. Settings, saved searches, and indexes stay on your PC. That is different from sending documents to a remote search service, but it means local storage matters: an index can contain sensitive words from your files. Protect the Windows account and device where you use Hannun, especially if other people can sign in to that PC.
Choose what to index
You control which folders Hannun searches and whether it reads inside documents. Start with the folders you actually need. If filename search is enough, leave document-content indexing off. If you enable it, use supported files and check the indexing status so you know whether coverage is complete. Scanned image PDFs need OCR before their page images contain searchable words; Hannun does not include OCR, and encrypted documents are not supported.
You can pause content indexing or clear the saved document-text index in Settings → Search inside files. Clearing that derived index does not delete your original documents. As with any local software, clearing the index is not a substitute for securing the PC or the source files.
Know what remains on disk
The index is derived search data, not a backup of your documents. If you uninstall Hannun, Windows may leave its settings, indexes, or duplicate-recovery files on the PC. If you no longer need those local records, check Hannun's data folder and remove them deliberately; restore any files you still need from recovery before deleting it. The privacy policy explains what the app keeps locally and what the separate Pro purchase flow handles.
Know where the app boundary ends
Downloading Hannun involves visiting its website. Buying optional Pro opens Gumroad in your browser, and the separate licence service processes the order and sends the licence. Those are web services outside the app's offline search runtime; check the privacy policy for what the purchase flow handles. The machine code used for a Pro licence is calculated on your PC. The privacy policy says the underlying Windows identifier itself is not sent.
Local does not mean risk-free
An offline app can reduce the amount of data sent to a search provider, but it does not protect a PC from someone who already has access to your Windows account, malware on the device, a lost or stolen computer, or an unprotected backup. Keep Windows security updates current, use a sign-in method appropriate to your situation, and protect backups as carefully as the originals. If your device is shared, consider whether other accounts can access the folders and local index you use.
It is also reasonable to ask for evidence before trusting a privacy claim. Read the policy, check whether the app asks for an account, and look for an explanation of where extracted text is stored. Hannun's policy describes the local index, permissions, recovery behavior, and separate Pro purchase flow. Its search app is designed to work offline; this is a product claim, not a guarantee that the Windows PC itself is disconnected or secure in every respect.
When this approach fits
Local search is useful when you want to search files on your PC without uploading their contents to a search service. It can also work when you do not want an app account. It is not a replacement for a managed document system, backup, antivirus, or device encryption, and it does not make unsupported file formats searchable.
I'm the maker of Hannun. It lets you search filenames and supported document text in folders you choose, then preview matching passages where available. The free edition's content search covers up to 5,000 recently modified eligible documents. See the Hannun site for current details. Its installer is unsigned, so Windows may show “Windows protected your PC”; choose More info → Run anyway only if you intend to install it.