Privacy and Local Processing: Does Your Data Leave the Browser?
Many AltFTool tools process text, files and calculations locally in your browser, so the input never leaves your device. Features that need AI, live data, lookups or server conversion send the minimum input required to a remote service, and the tool page says so.
Updated 5 min read
On this page
Local-first where practical
A large share of AltFTool's browser tools run entirely in your browser. When you format JSON, count words, generate a password or compress an image with one of these tools, the work happens on your own device and the input is not uploaded. Tools that work this way usually say so on the page, for example the Password Generator and the SSL Certificate Inspector.
Local processing has a practical benefit too: once the page has loaded, many of these tools keep working on a slow connection, and the speed depends on your device rather than a server queue.
When data is sent to a remote service
Some jobs cannot be done in a browser alone. These features send the input they need, and only that, to AltFTool's servers or to a third-party provider:
- AI features, which send your prompt or text to a model provider.
- Live data, such as currency rates, weather, news or search results.
- Network lookups, such as the WHOIS Lookup or the DNS Propagation Checker, which query public registries and resolvers.
- Server-side conversions for some file formats that browsers cannot handle.
- Account, storage and sync features that need to save data for you.
Handling sensitive data safely
Read the tool's privacy note
Tool and product pages describe local processing when it applies. If a page does not say, assume input may be sent to a server.
Remove what you do not need
Strip hidden metadata from photos and documents with the Batch Metadata Scrubber, and blur private details in screenshots with the Screenshot Privacy Masker.
Use test or sample data where possible
For passwords, API keys, health, financial or identity documents, prefer a local tool or redact the input first.
Clean links before sharing
The URL Tracking Parameter Stripper removes tracking tags from links in your browser.
What is stored and where the full terms live
Preferences such as your theme, favorite tools and recent tools are kept in your browser's local storage, as explained in saved preferences and browser storage. The public site also uses analytics and advertising in production; see ads and analytics.
This article is a plain-language summary. The privacy policy and cookie policy are the authoritative documents, and the terms and conditions cover acceptable use.
Tools used in this guide
- Password GeneratorGenerate random, highly secure passwords with advanced character controls, live strength scoring, and entropy estimates. Everything runs in your browser — nothing is stored.
- Batch Metadata ScrubberRemove EXIF, GPS, author and revision data from images and documents in bulk.
- Screenshot Privacy MaskerHide sensitive screenshot regions locally with solid masks, blur, or pixelation, then export a flattened image.
- Image Metadata ViewerExtract and view complete image metadata including EXIF, IPTC, GPS, and file properties.
- URL Tracking Parameter StripperRemove utm, gclid, fbclid, mc_eid and hundreds of other tracking parameters from links, in bulk, entirely in your browser.
Frequently asked questions
Does AltFTool upload my files?
It depends on the tool. Local-first tools process files in your browser without uploading them. Tools that need server conversion, AI or live data send the input they require, and the page should say so.
How can I tell if a tool runs locally?
Check the privacy note on the tool page. You can also load the tool, disconnect from the internet and try it: if it still works, processing is local.
Is it safe to use AltFTool for confidential documents?
Use a tool that states local processing, remove metadata first, and redact what you do not need. Avoid remote features for confidential material.