Highlight PDF
Mark up contracts, studies and reports like you would on paper: drag over any passage to highlight it in yellow, green, pink or blue, with the text fully readable underneath. Free, private, in your browser.
Files processed in your browserSelect a PDF or drag & drop
One PDF, up to 100 MB
Your files never leave your device. Highlight PDF runs entirely in your browser using JavaScript. Nothing is uploaded to a server. When you close this tab, your file is gone from memory.
How to highlight pdf
- Select your PDF. Choose or drag in the document. A preview of page 1 is rendered in your browser.
- Drag to highlight. Drag over any passage to mark it. Navigate pages and keep highlighting as you go.
- Pick a color. Yellow, green, pink or blue. Text stays readable through the highlight.
- Download. Press Add highlights and download the marked-up PDF. Nothing is uploaded.
Want more detail? Read our full guide: How to highlight text in a PDF.
Why highlight a PDF?
Highlighting is what active reading looks like. When you're working through a contract, a research paper or a dense report, the yellow streak is how you separate the two sentences that actually matter from the hundred that surround them. It marks the clause to renegotiate, the statistic to quote, the deadline you can't miss. And when you come back a week later, your eye goes straight to the color instead of re-reading the whole thing. Using more than one shade lets you build a simple code: green for what's agreed, pink for what's disputed, blue for follow-ups.
Doing this to a PDF is often harder than it should be. Free readers frequently omit highlighting, paid editors gate it behind a subscription, and the annotation-layer highlights some tools add can render differently (or vanish) when the file is printed or opened elsewhere. You end up unsure whether the person you send it to will even see your marks.
This tool renders page one in your browser and lets you drag over any passage to highlight it in yellow, green, pink or blue. Crucially the color is painted with a multiply blend at reduced opacity (exactly how a physical highlighter deposits translucent ink) so the words, figures and images beneath show through clearly instead of being blocked out. You can move through every page and keep marking, and each highlight is kept per page. Undo last and Clear this page fix any mis-drags before you download.
The marks are drawn as real rectangles into the page, so they survive printing, copying and every reader, while the text layer underneath is left untouched and stays fully selectable and searchable. Because even the page preview is generated locally, the document (however sensitive) never leaves your browser to be marked up.
Frequently asked questions
Are my files uploaded?
No. The page preview and the highlighting both happen entirely in your browser.
Does the text stay readable?
Yes. Highlights are drawn with a multiply blend at reduced opacity (the same way a real highlighter works) so text, drawings and images underneath stay visible through the color.
Is the highlighted text still selectable?
Yes. The highlight is a transparent overlay; the text layer underneath is untouched, so you can still select, search and copy it.
Can I highlight on several pages?
Yes. Move through the pages with the Prev/Next buttons and drag highlights wherever you need them; each one is kept per page and applied on download.
How do I remove a highlight?
Before downloading: Undo last removes the most recent one, Clear this page removes the current page's. After downloading, use this tool again on the original file.