PDF DPI Changer

How to Change the DPI of a PDF

1. Drop your PDF onto the tool, or click Choose File.
2. Pick a DPI. The presets are 72 (Screen Low), 96 (Screen), 150 (Balanced), 200 (Print), 300 (HQ Print) and 600 (Ultra). For another value, type it under Custom DPI, anywhere from 36 to 1200, and click Apply. It opens on 150.
3. Choose the JPEG Quality. Options run from Maximum (98%) to Low (60%). High (92%) is marked as recommended.
4. Set Page Size and options. Keep original page dimensions is the default, with Force A4 and Force Letter as alternatives. Grayscale output is a switch. Pages always get a white background.
5. Check the preview. The Live Preview, the Source and Output comparison and the Estimated output size update as you change settings.
6. Click Download. The DPI is added to the file name, for example _150dpi.pdf.

Why Use This PDF DPI Changer

• Your file stays on your device. The pages are rendered by code running in your browser. Nothing is sent to a server.
• A real change in resolution. Each page is re-rendered at the DPI you choose, and the page keeps its original physical size when you leave Page Size on Keep original page dimensions.
• Lower it to shrink the file. Dropping from 300 to 150 DPI cuts the pixel count to a quarter, and grayscale output cuts the file further.
• Raise it for printing. Pick 300 DPI or higher when the pages are going to a printer.
• Size estimate. A rough output size is shown before you export, so you can adjust first.

Good to know: every page is redrawn as a JPEG image, so text in the new file can no longer be selected or searched, and links stop working. Raising the DPI sharpens vector text and graphics, but it cannot add detail to a photo or scan that is already low resolution. Very high DPI on a long document uses a lot of memory, so start at 300; extremely large pages are scaled down automatically to stay within what the browser can draw. Force A4 or Force Letter fits each page inside the sheet without stretching and centres it, leaving white margins where the shape differs. To shrink a file with its text intact, try Compress PDF.

FAQ

How do I reduce the DPI of a PDF?

Drop your PDF onto the tool, click a lower preset such as 96 or 150, and click Download. Each page is re-rendered at that DPI, which usually makes the file smaller.

Which DPI should I choose?

Use 72 to 96 for screens and email, 150 for everyday documents, and 300 for printing. Above 300 the files grow quickly and the gain is small for most documents.

Will a higher DPI make my low-quality scan sharper?

No. A scan that is blurry at 100 DPI stays blurry at 600. A higher DPI only gives vector text and graphics more pixels to be drawn with.

Will the text in my PDF still be selectable?

No. Pages become JPEG images, so the new file has no selectable or searchable text. Keep your original if you need it.

Does the page size change?

Not by default. Keep original page dimensions leaves each page at its real size, and only the pixel density changes. Force A4 and Force Letter place every page on that sheet, scaled to fit and centred without stretching.

Is my PDF uploaded anywhere, and is there a size limit?

No, the PDF stays on your device while it is processed in your browser. Your file size limit is shown on this page, and a free account raises it.