About pdfcosmos
pdfcosmos is a growing collection of fast, private PDF tools that run entirely in your browser. We started it for a simple reason: working with PDFs shouldn’t mean handing your documents to a stranger’s server.
Our mission
Our mission is to make everyday PDF tasks (merging, splitting, rotating, converting, signing, and many more) genuinely private, free, and easy for everyone. We believe you shouldn’t have to choose between a tool that works and a tool that respects your files and their privacy. So we built tools that do their work on your own device, and are safe, secure, and free to use.
Why we built pdfcosmos
Like most people, we reached for online PDF tools when we needed to merge a few files or fix a page and kept running into the same trade-offs: upload your document to an unknown server, wait, and hope it’s deleted afterwards, or hit a paywall or a sign-up wall. Modern browsers are powerful enough to do this work locally, so we set out to build the tools we wished existed: private by default, free, and free of accounts.
Why local-first?
Most online PDF tools upload your files, process them on a server, and ask you to trust a privacy policy. pdfcosmos takes a different approach: the work happens on your own device using WebAssembly. Your files never leave your browser, so privacy isn’t just a promise. It’s how our tools are built, and you can verify it yourself in your browser’s Network tab.
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Local-first by design
Our tools run in your browser using WebAssembly. Your files are processed on your device and are never uploaded to a server, and you can verify it in your browser’s Network tab.
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No accounts, no friction
There’s nothing to sign up for and nothing to install. Open a tool and go. Everything is free to use.
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Built on open source
We stand on the shoulders of trusted, open-source engines like qpdf and pdf.js, software you can inspect and verify.
Who’s behind pdfcosmos
Bhartendu & Atul
A small, independent team
pdfcosmos is built by two people, Bhartendu and Atul, who wanted PDF tools they could trust with their own documents. We’re not a large company, and that’s the point: we’d rather build software that never asks for your files than software that collects them. We work slowly and deliberately, shipping one carefully made, reviewed tool at a time.
How it’s built
The tools are powered by trusted, open-source engines including qpdf for structural PDF operations, pdf-lib for creating and editing pages, and pdf.js for previews, all compiled to run right inside your browser. Nothing about how it works is a secret: you can read the license and role of every library on our Credits & licenses page.
Our commitment to you
As pdfcosmos grows, these are the promises we hold ourselves to:
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Private by design
Your files are processed in your browser and are never uploaded to a server. We never see your documents, their names, or their contents.
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Free to use
No account, no sign-up, and no paywall. Open a tool and get to work.
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Ads that never touch your files
Pdfcosmos is free, supported by light advertising and analytics. But your files are never part of that. They’re processed on your device and are never uploaded, seen, or used to target ads and you choose which non-essential cookies to allow.
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Open and verifiable
We build on open-source engines you can inspect, and you can confirm nothing leaves your device by watching your browser’s Network tab.
What’s next
We’re building pdfcosmos one carefully made tool at a time. If there’s a tool you’d love to see, or feedback you’d like to share, we’d genuinely like to hear it.