RunLocalTools

Add a Grid to a PDF — Graph, Dot, Ruled & Isometric Overlay

Add graph, dot, ruled, engineering or isometric grid lines behind any PDF, free. Vector lines, your content stays on top, and the file never leaves your browser.

What it does

This tool takes a PDF and draws a grid behind everything already on the page. You pick a pattern (square graph, dot grid, ruled notebook lines, engineering graph paper, or isometric), set the spacing, colour and margins, and download a new PDF. Worksheets, lecture slides, floor plans and blank pages all become printable workbook pages you can write or sketch on.

The grid sits behind your original text and images, so nothing on the page gets covered.

How it works

A PDF page is a list of drawing instructions, and each instruction paints over the ones before it. Drawing new lines onto an existing page would put them on top of your text. Instead, the tool builds a fresh page of the same size for every original page and draws the grid on it first. It then places the original page over the grid as a single embedded object.

Because the grid is real vector geometry rather than a picture, the lines stay sharp at any zoom level or print size. Spacing is converted exactly (1 inch = 72 points, 1 mm ≈ 2.835 points), so a 5 mm grid prints as a 5 mm grid.

  • Mixed page sizes are respected. Each output page copies the size of its source page, so a PDF with A4 and Letter pages keeps both.
  • Ruled pattern: horizontal lines, plus an optional red vertical margin rule at the offset you choose.
  • Engineering pattern: every Nth line is drawn darker and heavier, like real engineering paper.
  • Isometric pattern: three line families at 30°, 150° and 90°, clipped precisely to the printable area.

How to use it

  1. Drop a PDF onto the tool, or click to choose one.
  2. Choose a pattern. Options for that pattern (major-line interval, dot size, margin rule) appear automatically.
  3. Set the spacing and pick mm, inches or points.
  4. Adjust the margins, line colour, weight and opacity. The preview updates as you type.
  5. To grid only some pages, enter a range such as 1-3,5. Leave it blank for every page.
  6. Click Download gridded PDF.

If you need to reorder or delete pages first, do that with the PDF page manager, then add the grid. For a “DRAFT” or confidentiality mark on top of the same pages, use the PDF watermark tool afterwards. Adding the grid before page numbers keeps things simple if you also plan to use PDF page numbers and headers.

Supported input and limitations

  • Works with standard PDFs. Password-protected or corrupted PDFs are rejected with a message rather than producing a broken file.
  • The preview is a true-scale mock-up of the pattern at your page size. It does not render your actual page content (that stays untouched underneath).
  • Very large PDFs are processed in your browser’s memory, so a huge file may be slow on a low-powered device.
  • Scanned PDFs work too: the grid goes behind the scanned image. If the scan has a solid white background, it will hide the grid, because the page image covers it.

Privacy

Everything runs in your browser. Your PDF is never uploaded. The file is kept in your browser’s local storage only so it survives a page refresh, and the Clear saved file button removes it at any time.

FAQ

Will the grid cover my text? No. The grid is drawn first and your original page is placed over it, so text and images always sit on top.

Can I print it on graph paper sizes other than A4 or Letter? Yes. Each page keeps its own size, whatever it is. Custom sizes work the same as A4 or Letter.

Is the grid a picture or real lines? Real vector lines. They stay crisp at any zoom and print cleanly, and they add very little to the file size.

Why can’t I see the grid on my scanned PDF? A scan is usually one full-page image with a white background, which sits on top of the grid and hides it. Grid lines only show through where the page content is transparent.

Can I put the grid on only some pages? Yes. Enter a range like 2-4,7 in the pages field. Pages you leave out are copied through unchanged. Reversed ranges such as 5-2 are treated as 2-5.

Does it work offline? After the first use downloads the PDF library, it works without a connection.