Many application portals, job forms and document-upload systems set strict file-size limits. A 100KB target can be difficult because PDF size depends on page count, images, scans, fonts and embedded objects.
Why some PDFs shrink easily and others do not
A mostly-text PDF may already be compact. A scanned PDF can be much larger because every page is effectively an image. Image-heavy brochures and certificates also need stronger compression than simple text documents.
Start with the least destructive compression
If readability matters, avoid immediately turning every page into a low-resolution image. A better workflow is to preserve selectable text where possible and reduce image weight first. Stronger rasterisation can be used only when the target cannot otherwise be reached.
Use Compress PDF to 100KB when the upload portal has a small target. For general compression where an exact number is not required, use Compress PDF.
Aim slightly below the portal limit
If a portal says “maximum 100KB,” a result very close to the limit may still fail because different systems round file size differently. Leaving a small safety margin can reduce retry problems.
Check the result before uploading
- Open the compressed PDF.
- Zoom in and confirm important text is readable.
- Check that all pages are present.
- Confirm signatures, stamps and IDs are still clear.
- Verify the final file size in your device’s file properties.
What if 100KB is impossible?
A multi-page scanned document may not reach 100KB while remaining readable. If the portal allows a larger limit such as 200KB or 500KB, use a less aggressive target. Tooloos also provides Compress PDF to 200KB and Compress PDF to 500KB.
For scanned documents
Scans benefit from lower image resolution, grayscale when colour is unnecessary and careful cropping. However, too much compression can make small text, seals or signatures unreadable. Always inspect the output visually.
Privacy matters
When a PDF contains identity documents, school records, financial paperwork or other sensitive material, prefer tools that process locally in the browser where technically practical. Tooloos’ PDF compression workflow is designed around browser-local processing for the file operation.
For understanding a readable PDF after compression, you can also use Document Intelligence to extract the text and generate a structured analysis.