There are a hundred ways to mark up a PDF. Most of them involve downloading software, uploading your file to some website, or paying for a subscription to an app you'll use twice a month.
What if you could just open the PDF in your browser and start drawing on it? That's what we set out to build with Helperbird.
The problem with most PDF tools
You've been there. Someone sends you a PDF. You need to circle one section, add a comment, maybe draw an arrow. Simple enough, right?
Then you're downloading Adobe Reader, or signing up for an online tool, or trying to figure out why the built-in browser viewer doesn't let you do anything useful.
By the time you're set up, you've forgotten what you wanted to mark up in the first place.
Just open it and draw
Helperbird's PDF Reader opens PDFs right in your browser. Chrome, Edge, Firefox, Safari — it works everywhere. And now it has full drawing tools.
Freehand pen for quick marks. Rectangles and ovals for highlighting sections. Lines and arrows for pointing things out. A full color palette and adjustable stroke width so your annotations actually look the way you want them to.
You can select any drawing and move it, delete it, or undo your last action. It's the kind of thing that should have always been built into browsers but never was.
More than just drawing
Drawing is great for visual markup, but Helperbird's PDF Reader does a lot more. You can add sticky notes anywhere on the page. Use text-to-speech to have sections read aloud. Run OCR to extract text from scanned documents. Open the Immersive Reader to reformat dense text into something easier to read.
You can even use a color overlay or reading ruler on top of the PDF, just like you would on a regular webpage. All of it works together in the same tool.
It saves properly
This might sound obvious, but it matters. When you download the annotated PDF, your drawings are part of the file. Send it to a colleague, a teacher, a client — they see exactly what you see. No plugins needed on their end.
The PDF viewer also resizes when you change your browser window or toggle the split view, so your markup always looks right on screen.
Who uses this
We've seen teachers annotating student submissions. Lawyers marking up contracts. Researchers circling data points in papers. Students drawing all over their lecture slides at 2am. Designers marking up spec documents.
Really, anyone who opens a PDF and thinks "I wish I could just draw on this" — that's who this is for.
Keyboard friendly and accessible
Every tool in the drawing toolbar works with the keyboard. Tab to cycle through tools, arrow keys to move shapes, Delete to remove them. All buttons and color swatches have proper screen reader labels. Touch targets are sized for tablets too.
If you use dyslexia-friendly fonts or accessibility profiles in Helperbird, those settings carry over into the PDF Reader.
Give it a try
Helperbird is free to try and the PDF drawing tools are available right now. Install the extension, open a PDF, and click Draw. That's it.
If you want the full walkthrough with keyboard shortcuts, here's our step-by-step guide.
And if you want to see everything else the PDF Reader can do, check out the full feature page.
