WebP Converter With No Upload
Short answer: During the normal BatchWebP conversion workflow, selected image bytes and filenames are processed inside the browser and are not sent to a BatchWebP server. The browser decodes each file, draws it to a canvas, creates the output blob, and packages completed files locally. This statement applies to image conversion data; it does not mean that opening a website causes no network requests. The page still needs to load its HTML, CSS, JavaScript, and other site assets.
Product behavior verified: August 2026 against the current BatchWebP source and browser workflow. This is a technical description, not an independent security certification.
What image data stays in the browser?
| Data | Where it is handled | When it is cleared |
|---|---|---|
| Source image bytes and filename | Read by browser file APIs after you select or drop a file. | Released with the page session; close the tab to clear the working queue. |
| Decoded pixels and canvas | Held in browser memory while resizing, encoding, or comparing. | Replaced during processing and released by the browser. |
| Preview and download URLs | Created as local blob URLs in the current page. | Revoked or discarded when the item or page is removed. |
| ZIP and CSV report | Generated in the browser from completed queue items. | Saved only when you choose to download them. |
What network requests still happen?
Loading BatchWebP requires ordinary web requests for the page and application assets. Those requests can expose standard connection metadata such as an IP address, user agent, request time, and requested URL to the hosting provider. They do not include the image files selected for conversion. BatchWebP currently has no Google Analytics integration in the application; the privacy policy is the controlling disclosure if that changes.
How can I verify local processing?
- Open browser developer tools and select the Network panel.
- Clear the existing request log, then add a small test image to BatchWebP.
- Filter for Fetch/XHR requests and inspect requests made during conversion.
- Confirm that the selected filename or image payload is not sent to a BatchWebP endpoint.
- Repeat after changing quality, exporting CSV, and creating a ZIP if those operations matter to your review.
This check demonstrates observable browser traffic for the tested version and browser. It is more precise than relying on an absolute “100% private” slogan, but it is not a substitute for a formal security audit required by an organization.
Browser safeguards and limitations
- Each batch accepts up to 100 images, 40 MB per file, 250 MB combined, and 40 megapixels per decoded image.
- Closing the tab clears the working queue, but downloaded files remain wherever your browser saved them.
- A browser extension, managed-device agent, operating system, or modified browser can observe activity outside BatchWebP's control.
- Client-side processing reduces image-upload exposure; it does not make a device or network automatically compliant with a regulation.
- Do not process material on a device you do not trust.
When is a no-upload workflow useful?
Local processing is useful for unreleased product photography, client handoffs, internal screenshots, and batches that would be slow or undesirable to upload merely for format conversion. Teams with contractual or regulated-data requirements should still review the application, hosting, browser environment, and internal policy instead of treating local processing as automatic approval.
Open the local batch converter, review the privacy policy, or see the browser support notes.