How is this different from other online PDF tools?

Most online PDF tools send your files to a remote server for processing. This tool processes everything locally in your browser using client-side JavaScript. Your files are never transmitted to any server, which means your document content stays entirely under your control.

Are my PDF files uploaded?

No. Your files are read directly by your browser. Your files are never transmitted over the network. The tool works entirely within the browser tab you have open.

Can I verify that files are not uploaded?

Yes. Open your browser's developer tools (F12), go to the Network tab, and watch for any outgoing requests while using the tool. You will see no file data leave your browser. The site may record an anonymous page-view count, which never includes your files and can be disabled.

Does this tool work offline?

Yes, once the page has loaded the tool processes your files entirely in your browser; tool functionality needs no network connection. You can disconnect from the internet and continue using it.

What happens when I refresh the page?

Because nothing is stored on a server, refreshing the page clears your current session. Any files you had selected will need to be selected again.

Does this tool store my files?

No. Files are held in browser memory only for as long as the page is open. Closing or refreshing the page discards them. Nothing is written to disk by the tool, and nothing is sent to a server.

Can this tool unlock password-protected PDFs?

No. This tool does not attempt to remove or bypass PDF password protection. If you know the password, the Unlock PDF tool on this site can remove it locally; then this tool can process the file.

What technologies does this tool use?

This tool uses pdf.js to locate text positions in a Web Worker and client-side JavaScript with pdf-lib to draw the highlights — your files never leave your browser.

Does this tool use WebAssembly?

No. pdf.js and pdf-lib are plain JavaScript libraries — no WebAssembly is involved. Everything runs in client-side JavaScript within your browser.

How do I highlight a word or phrase in my PDF?

Pick a PDF with the file picker, type the word or phrase you want to find, then click Highlight Matches. The tool searches every page's text layer in your browser, paints a translucent yellow box over each match, and offers the highlighted PDF as a download.

Why aren't some matches found, like ones that wrap across a line break?

Matching is case-insensitive but works within each text run as the PDF stores it, so a phrase split across a line break or column break is not detected as a single match. Searching for shorter, single-word terms usually catches more occurrences.

Can I turn the highlights off later in my PDF reader?

No. The highlights are translucent yellow rectangles drawn directly onto the page rather than removable annotation objects, so a PDF reader has no separate marker to toggle. If you need the original back, just keep your unhighlighted source file.

Does the Search & Highlight PDF tool cost anything to use?

The Search & Highlight PDF tool is completely free — no account, no sign-up, and no cap on how many PDFs you run through it, and it always will be. Every step happens inside your browser: your PDF is read into browser memory, pdf.js locates every match in the text layer, and pdf-lib paints a translucent yellow highlight over each one before the file downloads back to your device — your document and your search term never leave your browser.

Search and Highlight Text in a PDF Privately — In Your Browser

Select a PDF and enter a search term; every match in the text layer is located and a translucent yellow highlight is drawn over it, then the highlighted PDF downloads locally.

Quick answer

What it does: Select a PDF and enter a search term; every match in the text layer is located and a translucent yellow highlight is drawn over it, then the highlighted PDF downloads locally.
Free?: Yes — 100% free, no account or sign-up.
Files uploaded?: No — everything is processed in your browser.
Works offline?: Yes — once the page has loaded.
Best for: A researcher highlights every occurrence of a key term across a long paper so it stands out during review.
Good to know: Scanned (image-only) PDFs have no text layer to search — run OCR first.

How it works

Select a PDF file from your device using the file picker.
The file is read into browser memory — no data leaves your browser.
Enter the word or phrase to find; matching is case-insensitive.
pdf.js reads each page's text layer and locates every match's position.
pdf-lib draws a translucent yellow rectangle over each match and the highlighted PDF is offered as a download.

When to use this tool

A researcher highlights every occurrence of a key term across a long paper so it stands out during review.
A legal team marks every instance of a client name in a contract to verify consistency throughout the document.
An editor searches for a misspelled word across a multi-page PDF to locate every occurrence at once.
Works only on PDFs with a text layer — scanned image-only PDFs will show no matches; run OCR first to add recognisable text.

Frequently asked questions

How is this different from other online PDF tools?: Most online PDF tools send your files to a remote server for processing. This tool processes everything locally in your browser using client-side JavaScript. Your files are never transmitted to any server, which means your document content stays entirely under your control.
Are my PDF files uploaded?: No. Your files are read directly by your browser. Your files are never transmitted over the network. The tool works entirely within the browser tab you have open.
Can I verify that files are not uploaded?: Yes. Open your browser's developer tools (F12), go to the Network tab, and watch for any outgoing requests while using the tool. You will see no file data leave your browser. The site may record an anonymous page-view count, which never includes your files and can be disabled.
Does this tool work offline?: Yes, once the page has loaded the tool processes your files entirely in your browser; tool functionality needs no network connection. You can disconnect from the internet and continue using it.
What happens when I refresh the page?: Because nothing is stored on a server, refreshing the page clears your current session. Any files you had selected will need to be selected again.
Does this tool store my files?: No. Files are held in browser memory only for as long as the page is open. Closing or refreshing the page discards them. Nothing is written to disk by the tool, and nothing is sent to a server.
Can this tool unlock password-protected PDFs?: No. This tool does not attempt to remove or bypass PDF password protection. If you know the password, the Unlock PDF tool on this site can remove it locally; then this tool can process the file.
What technologies does this tool use?: This tool uses pdf.js to locate text positions in a Web Worker and client-side JavaScript with pdf-lib to draw the highlights — your files never leave your browser.
Does this tool use WebAssembly?: No. pdf.js and pdf-lib are plain JavaScript libraries — no WebAssembly is involved. Everything runs in client-side JavaScript within your browser.
How do I highlight a word or phrase in my PDF?: Pick a PDF with the file picker, type the word or phrase you want to find, then click Highlight Matches. The tool searches every page's text layer in your browser, paints a translucent yellow box over each match, and offers the highlighted PDF as a download.
Why aren't some matches found, like ones that wrap across a line break?: Matching is case-insensitive but works within each text run as the PDF stores it, so a phrase split across a line break or column break is not detected as a single match. Searching for shorter, single-word terms usually catches more occurrences.
Can I turn the highlights off later in my PDF reader?: No. The highlights are translucent yellow rectangles drawn directly onto the page rather than removable annotation objects, so a PDF reader has no separate marker to toggle. If you need the original back, just keep your unhighlighted source file.
Does the Search & Highlight PDF tool cost anything to use?: The Search & Highlight PDF tool is completely free — no account, no sign-up, and no cap on how many PDFs you run through it, and it always will be. Every step happens inside your browser: your PDF is read into browser memory, pdf.js locates every match in the text layer, and pdf-lib paints a translucent yellow highlight over each one before the file downloads back to your device — your document and your search term never leave your browser.