About AntiUpload

File tools designed around one boundary: your files never leave your device.

What AntiUpload is

AntiUpload is a privacy-first, browser-based toolkit for working with PDFs, images, video and audio. Merge, split, compress, convert, protect and edit without transferring the source file to a processing server. There is no account, cloud copy, file telemetry or paid privacy tier.

How it actually works

Unlike most online PDF tools, AntiUpload doesn't upload your files to a server. Every conversion runs entirely in your browserusing WebAssembly and modern JavaScript APIs. When you drop a file into AntiUpload, it stays on your device. When you close the tab, it's gone.

This matters when you're working with résumés, contracts, medical records, tax documents, or anything else you'd rather not hand to a third party. If your files would make a lawyer nervous on a server somewhere, use AntiUpload.

Privacy is the product, not a paid tier

The heavy work happens on your computer, so AntiUpload does not need a conversion-server business model. Ads and aggregate analytics can support the site, but they stay outside the conversion engine and never receive file bytes, names, passwords, extracted content or output buffers. The tools remain free because local processing keeps infrastructure small; file privacy is never reserved for a paid plan.

What works well, and what doesn't (yet)

AntiUpload is honest about its limits. The conversion engines are strong on text-heavy documents — résumés, reports, articles, books. They're weaker on:

• Low-resolution, skewed, handwritten, or heavily damaged scans, even with OCR enabled
• Complex magazine layouts with irregular columns and pull quotes
• PDFs with form fields, math equations, or non-Latin scripts in unusual fonts

We're improving all of this. If a conversion doesn't come out right, let us know — real feedback is what drives the next engine update.

Who made it

AntiUpload is designed, implemented, tested, and maintained by an independent developer. Articles and technical claims are published under the byline AntiUpload Engineering so responsibility stays with the same team that maintains the code and conversion engines. There is no sales team and no paid tier.

We separate a feature claim from a tested claim. Supported inputs and controls come from the running implementation; accuracy or fidelity statements require a repeatable fixture and a recorded result. Our testing and editorial methodology explains that process, including its limits.

Recently shipped

Honest list of what changed in the last few engine sweeps. We don't gate behind “new” badges that never expire — when something here stops being recent, it gets dropped from the list.

• Compress PDF — smarter image re-encoding, optional grayscale + metadata stripping, larger reductions on photo-heavy PDFs.
• Compress / Resize / Convert Image — full HEIC support (iPhone photos), AVIF and BMP inputs, mozjpeg + oxipng for noticeably smaller outputs.
• Word → PDF — multi-file batch conversion with per-file dedup, optional metadata stripping for safer sharing.
• PDF → Markdown / Images / Repair / Watermark / Page Numbers / Rotate — batch mode (folder of PDFs in one go), pdf.js fallback for files strict parsers reject, per-page rotation maps, text + image watermarks with tile and angle controls.
• Merge PDF — drag-to-reorder file list, one-click reverse, keyboard fallback for touch users.
• PDF → Word — better handling of academic title pages, resume contact lines, scanned-page detection, and OCR language picker.

See something that should work better? File feedback — every report shapes the next sweep.

Get in touch

Bug reports, feature requests, something not converting right — leave a note on the feedback page. Every submission lands in our inbox and gets looked at.