Step-by-Step: Check the Resolution (DPI) of a PDF File

Software Needed
  • Adobe Acrobat Pro
  • Photoshop
Steps at a Glance
  • Use the Pre-flight Tool
  • Create a Checking Profile
  • Run the Analysis
  • Download the Image
  • Verify in Photoshop

If you’ve ever needed to check the DPI (dots per inch) resolution of an image embedded in a PDF file, you know it can be tricky without knowing the steps. In this step-by-step guide, I’ll show you how to use Adobe Acrobat to check the DPI and verify it in Photoshop.

Run the Analysis: Adobe Acrobat Pro

Step 1: Open Your PDF in Adobe Acrobat

Start by opening your PDF in Adobe Acrobat Pro, the paid subscription version. Navigate to All Tools, then select Print Production.

Screenshot showing how to open a PDF file in Adobe Acrobat

Step 2: Access the Pre-flight Tool

In Adobe Acrobat, locate the left-hand menu and select Pre-flight.

Screenshot of Adobe Acrobat with the Pre-flight tool option highlighted

Step 3: Create a Custom Pre-flight Profile

The built-in Pre-flight tool in Adobe Acrobat contains many preset profiles. A profile defines the conditions for analyzing your file. In our case, we want to checking the image DPI in a batch, so we’ll create a simple profile for that purpose. Go to Options (right corner of the panel) and select Create Profile.

Screenshot showing how to create a custom profile in Adobe Acrobat's Pre-flight tool

Step 4: Edit the Profile

The profile allows you to set the criteria for analyzing your PDF. In this case, we want to check if any images are under 300 DPI. On the left-hand menu, select Images. Then, in the Resolution of color and grayscale images is section, set the condition to warning and specify resolutions lower than 300 DPI.

Screenshot of editing a custom profile in Adobe Acrobat's Pre-flight tool

Step 5: Select the Profile and Run the Analysis

Once you’ve saved the profile, it will appear in the main Pre-flight panel. Select it and click Analyze to run the check.

Screenshot showing how to select a profile and run the analysis in Adobe Acrobat

Step 6: Review the Pre-flight Results

In the Pre-flight Results panel, the tool will display the analysis, flagging any images that meet your preset criteria (e.g., images with a resolution below 300 DPI).

Screenshot displaying the Pre-flight analysis results in Adobe Acrobat

Verify in Photoshop

Step 7: Locate and Download the Image

In the Pre-flight Results panel from the previous step, click Show to navigate to the specific image in the PDF. Then, right-click the image, select Save image as, and download it to your computer.

Screenshot showing how to select and download an image from a PDF in Adobe Acrobat

Step 8: Open in Photoshop and Verify the Resolution

Open the downloaded image in Photoshop, then go to Image > Image Size to see the resolution in DPI.

Screenshot showing how to check the image size in Adobe Acrobat's Pre-flight results

Step 9: Confirm the DPI

Screenshot highlighting the DPI resolution of an image in Adobe Acrobat