Privacy-Focused Browser Tool Compresses PDFs Locally Without Uploading Sensitive Documents

A developer created a PDF compression tool that runs entirely inside the browser to protect sensitive personal and professional documents from third-party servers. The solution addresses repeated situations where embassy submissions, financial presentations, contracts, and internal reports exceeded size limits, forcing users to choose between installing desktop software or risking data exposure through online services. The tool reduces scanned and photographic PDFs by 66 to 97 percent depending on quality settings while honestly reporting weaker performance on text-heavy files compared with Ghostscript. It works on both desktop and mobile platforms, including iPhone and Android, requires no installation, and continues functioning offline after the first page load. On mobile devices the application respects memory constraints by limiting images to four megapixels, preserving readability for A4 documents intended for printing. The project originated from a single evening script built around Ghostscript and evolved into a full web application after similar compression needs recurred across multiple devices and locations.

HabrTranslated from Russian

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A developer frustrated with online PDF compression services has released a browser-based tool that processes files entirely on the user’s device, eliminating the need to upload sensitive documents such as birth certificates, diplomas, and financial reports.

The project began when a multi-page PDF containing scans of passport data and official documents had to meet a strict one-megabyte limit for an embassy submission. Standard search results pointed to free online compressors, yet the author rejected them because the files represented a complete identity package that could enable impersonation if mishandled.

Desktop alternatives such as Ghostscript, Apple’s Preview, and paid editors were available on a personal laptop, but the same constraints appeared later on other computers and especially on mobile phones. Presentations containing financial figures, internal reports, and contracts repeatedly exceeded email or portal limits, leaving users with the choice of installing command-line tools or sending data to unknown servers.

The resulting web application, designed with mobile use as the primary scenario, opens in Safari or Chrome, can be added to the home screen, and continues working without an internet connection after the initial visit. On phones it avoids memory-related tab reloads by capping images at four megapixels, which remains sufficient for legible A4 output.

Performance tests show size reductions between 66 and 97 percent on scanned and photographic content. On purely textual PDFs the tool underperforms Ghostscript and explicitly informs users of this limitation. No files ever leave the device, addressing the core privacy concern that originally motivated the project.

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