ZeroTools Privacy: Browser Processing and Features That Use External Services
Understand browser-based image and PDF processing, external speech and data services, model downloads, local storage, and advertising or analytics requests.
§1. Local Processing and External Services
Image compression and PDF editing can read and process selected files on your device. This avoids an upload to a file-processing server. Speech recognition is different: the browser supplies the recognition engine and may send audio to an external service. Exchange-rate and other information lookups also need online requests.
| Processing type | Examples | Network requirements |
|---|---|---|
| Browser file processing | Image compression, PDF editing | File processing is separate from page and library downloads |
| Models downloaded for local computation | OCR, background removal | Libraries, WASM, or model files may need to load first |
| Browser recognition service | Speech to text | Audio may be sent to a remote recognition service |
| External data lookup | Exchange rates, IP information | Requests are sent to the data provider |
Check the browser or provider’s retention and data-use policy before using an external service. Avoid entering confidential audio when the processing destination is not suitable for your needs.
§2. How Browser File Processing Works
JavaScript and Local Storage
File and FileReader APIs let a page read selected files for processing. Blob objects can hold results for download. These APIs do not themselves prevent networking or persistence; those properties depend on the implementation.
Closing a tab usually clears ordinary page state, but tools with saving features may retain content in LocalStorage or IndexedDB. Downloads and clipboard contents also survive independently of the tab. Check stored content when using a shared device.
WebAssembly and Canvas
Some OCR and background-removal operations use browser libraries and models for local computation. Canvas supports image drawing and resizing. Processing time and memory use depend on your device, file size, and image resolution. Large operations are not guaranteed to finish instantly.
Encryption and Its Limits
Web Crypto provides browser cryptographic operations. Password strength and file handling still matter. Local processing can avoid file uploads, but it does not eliminate risks from compromised devices, extensions, or modified application code. A browser sandbox does not automatically prohibit all network access.
§3. Offline Availability and Network Checks
Even local processing may need an initial library or model download. Offline use requires those resources to be available and the selected feature not to depend on an external service.
1. Prepare a test file without sensitive information.
2. Read the tool instructions and finish any library or model downloads.
3. Use the browser developer tools Network panel to inspect page requests during processing.
4. If you need offline use, disconnect and test the workflow through saving the result.
5. Check dependencies and browser support if the operation fails.
The Network panel does not necessarily show all requests made by a browser’s internal speech service. An empty page request log is not proof that no audio was transmitted.
§4. Advertising, Analytics, and Workplace Use
Local file processing is separate from page delivery, advertising, and analytics. Those services may involve requests, cookies, or other storage. Read the privacy policy for details.
Follow your organization’s rules for sensitive information. Browser-based processing alone does not establish that a tool meets every security or data-handling requirement. Keep original files and verify results before relying on them.
§5. Further Reading and Tools
- SpeechRecognition processing and compatibility (MDN)
- Image Compressor
- PDF Merge & Split
- Speech to Text
- About ZeroTools
If an explanation does not match a tool’s behavior, contact us with the tool name and browser details.