How to reduce the size of a scanned PDF

What this workflow helps you do

A scanned PDF normally contains page images rather than ordinary selectable text. This workflow explains where Compress PDF fits and when OCR or a separate image step is required.

Compress scanned or photo-heavy pages where image quality can be traded carefully for a smaller document.

Plan the task in Compress PDF

Make a PDF smaller by rebuilding its pages with your chosen image quality. This works best for scanned or image-heavy documents and clearly shows the quality trade-off.

Searches for compressing a PDF to 100KB, 200KB, 500KB, or 1MB usually come from an upload limit. PDFKaka can make scanned and image-heavy PDFs smaller with adjustable quality, but it does not falsely promise an exact final size. The result depends on page count, dimensions, colours, and source content.

1. Compress scanned and image-heavy PDF files. The tool renders each page and rebuilds the PDF with compressed page images. That can substantially reduce scans, photographed notes, image portfolios, and similar documents.
2. Choose readable quality before the smallest size. Lower quality can produce a smaller file, but fine print, signatures, diagrams, and identification details may become harder to read. Compare the result with the original before using it.
3. Understand what compression changes. Because pages are rebuilt as images, selectable text, links, interactive fields, and digital signatures are not retained. Keep the original PDF whenever those features matter.

Identify image-only pages before choosing the next step

A scan can look like an ordinary PDF while storing each page as one image. Compress PDF may still handle the page visually, but text search, extraction, editing, and exact-text operations need real text objects or a reviewed OCR layer.

Try selecting a sentence in a reader. If the whole page behaves like one image, plan for OCR where supported and expect to verify recognition errors manually.

1. Check whether text is selectable on several pages.
2. Inspect scan focus, contrast, skew, shadows, and cropped edges.
3. Verify OCR names, dates, numbers, and reading order when OCR is used.

Settings and limitations to check

Can this compress a PDF to exactly 200KB or 500KB? Not exactly. Choose a quality level, check the resulting size, and try a lower setting if necessary. Some PDFs cannot reach a very small limit while remaining readable.

Why did my text-only PDF not become much smaller? Digitally created text PDFs can already be compact. This method is most effective for scanned or image-heavy pages.

Are compressed PDF pages uploaded? No. Rendering, image compression, document rebuilding, and download happen in this browser.

1. Use only the settings needed for the required result.
2. Keep the source file available for comparison.
3. Do not rely on an unsupported exact-size, fidelity, or security promise.

Review the completed file

Verify that page images remain readable and remember that searchable text, links, forms, and signatures are not preserved by raster rebuilding.

Open the downloaded result in a separate viewer, inspect important pages or details, and repeat the workflow with adjusted settings if the output is not suitable.

1. Confirm the expected file type and page count.
2. Check important text, images, order, and orientation.
3. Share or submit only the reviewed copy.