Image-only PDF vs searchable PDF: what is the difference and which one counts as a usable record?

When you scan a paper document, the result is almost always a PDF, but not all PDFs behave the same way. The difference between an image-only PDF and a searchable PDF affects how usable, findable, and defensible a record will be over its lifecycle.

What is an image-only PDF?

An image-only PDF is essentially a digital photograph of each page wrapped in a PDF container. It shows the page exactly as it looked on paper, but to a computer it is just a picture. The text cannot be selected, copied, or searched, because no actual text data exists in the file, only pixels.

What is a searchable PDF?

A searchable PDF starts the same way, as a scanned image, but Optical Character Recognition (OCR) is applied to interpret the characters in that image. The recognized text is stored as an invisible, selectable layer behind the page image. The document still looks identical to the original, but now the text can be searched, copied, indexed, and read aloud by assistive technology.

Which one counts as a usable record?

Both can technically be records, but usability and accessibility are key qualities of a trustworthy record. A record must be findable and intelligible for as long as it is retained.

• An image-only PDF preserves appearance but is hard to search, harder to manage at scale, and may not meet accessibility expectations.
• A searchable PDF preserves the same appearance while adding the text layer that makes the record discoverable, e-discovery friendly, and easier to use in FOIA, audit, and reference contexts.

For most operational and long-term needs, a searchable PDF is the stronger choice because it supports the access and reuse that define a usable record.

Practical guidance

• Capture at quality levels appropriate to the source so OCR can work reliably; poor scans produce poor text.
• Review OCR accuracy on critical documents, since recognition errors can affect retrieval and redaction.
• Retain the page image, not just extracted text, so the record continues to reflect the original.
• Document your imaging process so the digitized version can stand in for the original with confidence.

For more on capture quality, formats, and managing digitized content, see the digitization and imaging topic hub.