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There are 2.5 trillion PDFs in existence. Let that sink in—that’s over 300 PDFs for every person on the planet. PDFs have long been the preferred downloaded file format for presentations, memos, or any digital documents because they’re durable and serve as a familiar stand-in for the physical docs we no longer use. But there’s always been one glaring problem with the PDF: have you ever tried commenting on one?

Collaborating on PDFs is downright miserable. There is simply no efficient way to comment on a PDF document, share that document with others, have all comments live in one version, and allow everyone to see and make comments in real time. Teams leave feedback inside of email threads, Google Docs, and Slack chains that are too long to follow, tracking changes inside of a spreadsheet full of screenshots. It’s the equivalent of running through a wall in order to exit a building—it gets you out of the building, but it makes zero sense and leaves you with a pounding headache.

MarkUp is changing that. 

You can now upload any PDF into MarkUp, place comments on any page of the document, and freely share it with as many people as you want. And guess what? Your colleagues don’t need to download software in order to use it. They don’t need to worry about being on the right PDF version as everyone else. And, yes, it’s free. 

It is organizational transparency at its finest. And it’s all happening on MarkUp, Ceros’s collaboration platform. (In full disclosure, I work there as MarkUp’s Growth Lead.)

PDFs are the latest installment in MarkUp’s quest to make commenting on any form of digital content remarkably simple. MarkUp is now serving over 100,000 designers, developers, and marketers every day. Its mission started in March 2020 with solving the far-reaching problem of website feedback. And as MarkUp has grown, the product has undergone a transformation, increasing performance, design, and stability. As the users have multiplied, so have the use cases, which brings us back to the PDF.

When one person (let’s call her Sarah) creates a PDF, it is saved locally on Sarah’s device. She actually needs to have proper PDF editing software in order to leave comments. Once she does that and leaves some comments on the PDF, she’s then ready to share. But before she shares it with Ted, she needs to make sure she sends the right version.

The problem is Ted can’t open that same version with all of Sarah’s comments until he has the right PDF editing software on his device. After 10 minutes of unzipping and downloading desktop software, only then is he able to open Sarah’s PDF and see her comments. 

What happens when five, 10, or 20 people get involved with this PDF? If you’re reading this and thinking: wouldn’t everyone across the organization have to have the same type of desktop software and the same original PDF version in order to collaborate? You would be correct.

If you’re also thinking: sorry, but that’s damn near impossible. You are correct again.

This problem affects millions of people every single day. There was no easy way to make this collaboration process work until now.

With PDF collaboration inside MarkUp, Sarah can now upload her PDF and share that link with Ted. He can open the link as a guest and immediately see any of Sarah’s comments as well as his own. Additionally, Ted is able to seamlessly reply to Sarah’s comments, resolve them, or keep them active for others to see. When Ted passes that link along to others in the organization, all of their feedback will live in one, central location. A visual, living document with all comments across all pages from Sarah’s original PDF. 

No software downloaded, unzipped, and installed just to view the PDF. No different versions. No excruciating headaches trying to compile all feedback together into one place. Instead? Sarah enjoyed a beer while her colleagues left comments.

And that is why our team at MarkUp built PDF collaboration. 

Here’s to the content we all create ahead, and to the beautiful collaboration that will ensue. The PDF is here to stay, and so should your sanity.

MarkUp is completely free to use. You can sign up at

Alex Bullington is the Growth Lead at MarkUp.

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