PDFViewerHighlight a PDF online
Highlight a PDF by dropping it here: pick Highlight on the toolbar, choose a color, select the text, and press Download. Everything runs in your browser, so the file is never uploaded, and the highlights are written into the PDF so Acrobat, Preview or Chrome show them.
How to highlight text in a PDF
- Drop the PDF on this page or click Open a PDF.
- Click Highlight on the toolbar and pick a color: yellow, green, blue, red, orange, purple or black.
- Select the text you want marked. Move through the document with the thumbnails sidebar or Ctrl+F and keep highlighting.
- Highlighted the wrong line? Ctrl+Z undoes it; Eraser removes any single highlight you click.
- Press Download to save a copy with the highlights embedded.
The Search box helps when you need to highlight every mention of a term: search, jump to the match, highlight, next match.
Seven colors, one review pass
A single yellow marker is fine for reading, but review work goes faster with a color code. A common scheme: yellow for key facts, green for things you agree with, red for errors to fix, blue for questions, orange for follow-ups, purple for quotes worth reusing, black to strike through a line visually. The viewer keeps the chosen color until you switch, so you can sweep a chapter in one color and then do a second pass in another.
For a long document, highlight first and add a short text note next to the marks that need a comment. Both end up in the same downloaded file.
How the highlights show up in Acrobat, Preview and Chrome
When you press Download, pdf-lib writes the highlights into a new PDF. They are part of the document, so the file behaves the same in Adobe Acrobat Reader, Preview on macOS, Microsoft Edge, Chrome, Google Drive's preview and mobile readers: the colored marks sit over the text exactly where you put them.
The text itself is untouched. Copying a highlighted paragraph still copies the words, and the file's own search still finds them. If you later want the marks gone, open the downloaded copy here and use Eraser.
Why some PDFs cannot be highlighted
Highlighting works on text the PDF actually contains. A PDF made by scanning paper or photographing a page is just a picture: there are no letters for the Highlight tool to find, so nothing gets selected. The fix is OCR. Press OCR on the toolbar, let the viewer recognize the text in your browser, and highlight after that. The OCR a PDF page explains the steps and the waiting time; what is a scanned PDF explains why the difference exists.
Two other cases: a PDF that asks for a password before it opens cannot be opened here at all, and a PDF with only permission restrictions (no annotating allowed) can be freed with Remove Restrictions first.
Highlight a PDF on Mac, Windows, Chromebook or phone
The steps above are the same on every system because the viewer is a web page. On a Mac, open it in Safari or Chrome; the downloaded file lands in Downloads like any other. On Windows, Chrome, Edge and Firefox all work, and there is nothing to install, which helps on a locked-down work laptop. On a Chromebook, the file comes from and goes back to the Files app or Google Drive. On an iPhone, iPad or Android phone, use Safari or Chrome and tap to select text; normal-size documents are fine, while a scan with hundreds of pages may be more than a phone's memory can hold.
Students and reviewers on a tablet may also want the annotate a PDF on iPad guide, which covers highlighting with a stylus.
Alternatives: highlight a PDF without Adobe
- Preview on macOS: select text, click the highlighter in the toolbar; colors are in the drop-down next to it.
- Microsoft Edge: open the PDF, select text, choose Highlight from the pop-up or the toolbar.
- Chrome: the built-in viewer can highlight and draw on desktop; the result is saved through the download button.
- Adobe Acrobat Reader: the free reader includes the highlighter in its Comment tools.
- Google Drive: open a PDF in the preview and add highlights with comments, useful for shared files.
- Xodo, PDF-XChange Editor: desktop and mobile highlighters with more options for color and opacity.
- Smallpdf, iLovePDF: online editors with a highlighter; the file is uploaded to their servers first, which matters for confidential documents.
Frequently asked questions
How do I highlight a PDF without Adobe?
Open it in a browser viewer like this one, in Preview on a Mac, or in Edge; all three have a highlighter. Select the text, pick a color, save or download.
Can I highlight a PDF on a Chromebook?
Yes. This viewer runs in Chrome on ChromeOS, and the downloaded file goes straight to the Files app or Google Drive.
Does highlighting change the file?
Your original file is not modified. Download creates a new PDF with the highlights embedded; the text under the highlight stays the same and remains searchable.
Why can't I highlight text in my PDF?
The PDF is probably a scan with no text layer. Run OCR on the toolbar first, then highlight. If the file asks for a password to open, it cannot be opened here.
How do I remove a highlight from a PDF?
Pick Eraser on the toolbar and click the highlight. Ctrl+Z also undoes the last one. This works on files you highlighted here and on highlights made in other editors.
Can I highlight a PDF on my phone?
Yes, in Safari or Chrome on iPhone and Android for normal-size files. Very long scans may be too heavy for a phone's memory.