How to use Highlight PDF online for free — the complete 2026 guide
Draw attention to critical passages without opening a heavy PDF editor. Highlight PDF overlays a translucent rectangle exactly where you need it.
Ready to try it?
Open the Highlight PDF tool and follow along.
What Highlight PDF does
Highlight text visually in the PDF Editor, or place a translucent rectangle with the quick coordinate tool.
Draw attention to critical passages without opening a heavy PDF editor. Highlight PDF overlays a translucent rectangle exactly where you need it.
How to use Highlight PDF — step by step
Follow these steps to use the Highlight PDF tool on WordToPDFHub. The whole flow takes less than a minute for typical documents.
- 1Upload the PDF to the Highlight PDF tool.
- 2Drag a rectangle over the region you want to highlight.
- 3Repeat for every region and download the highlighted PDF.
Pro tips
A few habits that get the best results out of Highlight PDF:
- Lower opacity keeps the underlying text readable.
- Use different colours (via the picker) for a simple visual code.
- For text-level highlighting on scanned PDFs, run OCR first.
Common use cases
Users reach for Highlight PDF in a range of scenarios. The most common:
- Flagging the key clauses of a contract for a colleague.
- Marking sources you want to revisit in a research paper.
- Preparing study notes from a lecture handout.
Why use WordToPDFHub for highlight pdf
Most online PDF tools force you to upload files to a remote server, wait in a queue, and accept a watermarked result. WordToPDFHub takes the opposite approach: everything happens in your browser, results are instant, and the output is clean.
- 100% browser-based — no uploads, no accounts, no watermarks.
- Works on Windows, macOS, Linux, iOS, Android and Chromebook.
- Handles multi-page documents at desktop speed.
- Free forever for individual users.
Privacy and security
Highlight PDF runs entirely in your browser. Your PDF is loaded into memory, processed with WebAssembly, and the result is offered as a direct download. Nothing is uploaded, cached on a server, or logged.
Because the work is local, you can safely use it on contracts, invoices, medical records and other confidential documents without violating internal data-handling policies.
Frequently asked questions
- Is my file uploaded to a server?
- No. Every WordToPDFHub tool runs inside your browser using WebAssembly, so your document never leaves your device.
- Is the tool really free?
- Yes — every core tool on WordToPDFHub is free to use with no watermarks, no sign-up, and no file-size paywall for typical documents.
- Does Highlight PDF work on mobile?
- Yes. Highlight PDF runs in any modern mobile browser — Safari on iOS, Chrome on Android, and the built-in browsers on iPad and Android tablets.
- Are there file-size limits?
- The tool is limited only by your device's memory. Typical documents up to a few hundred megabytes process comfortably on a modern laptop or phone.
Try Highlight PDF now
Free, browser-based, no sign-up.
Open the tool