Open and read a PDF in your browser — zoom, page jump, full screen

How to use the PDF viewer

1. Drop a PDF onto the box, or press Choose a file. You can also paste a PDF file you have copied.
2. The first page opens at Fit width. The bar above it shows the page number and the total number of pages.
3. Move between pages with the ‹ and › buttons, or type a number in the Page box and press Enter.
4. Use − and + to zoom, Fit width to return to the default size, and Full screen to fill your screen. Press Exit full screen or Esc to go back.

What it does and when to use it

This is a quick way to look inside a PDF on a computer that has no PDF reader installed, on a shared or work machine where you would rather not install software, or when you only need to check one page of a long file. It is also handy before you use another PDF tool: open the file here to find the page numbers you want to extract, rotate or delete.

Because nothing leaves your device, it suits payslips, bank statements and contracts.

How it works

The tool is built on pdf.js (the pdfjs-dist package), the PDF engine used by Firefox, together with pdf-lib for reading basic document details. Your browser reads the file into memory and pdf.js parses it in a background worker served from this site. Only the page you are looking at is drawn, so long files open quickly.

The zoom figure is relative to the page’s real size at 96 pixels per inch, so 100% shows an A4 page about as wide as it would be on paper. Keyboard shortcuts work once the viewer has focus (click on it first):

Worked examples

A 12-page report. You drop report.pdf. Page 1 appears at fit width and the bar reads “Page 1 of 12” and “12 pages”. You type 7 in the Page box and press Enter to jump straight to the chart on page 7, then press + twice to zoom in on its labels.

Checking a scan before sending it. A phone scan of a 3-page form opens. You press → to step through it and notice page 2 is upside down, so you fix it with the PDF rotate page range tool before emailing it.

Limits and tips

• Pages are drawn as images: no search, no text selection and no clickable links.
• Very large files (hundreds of MB) are read fully into memory and can make a browser tab run out of memory.
• Password-protected files must be unlocked first with the password you already know.
• To see the title, author and other properties, use the PDF metadata viewer.