Common situations
The compressed file is still too large
Likely cause: Scanned and image-heavy documents have a floor below which they cannot be reduced without visible quality loss. Smart compression also has to keep text selectable, which limits how far it can go.
What to try
- Try Maximum compression, which rasterises pages for the smallest possible file.
- Choose the Extreme preset instead of Light or Balanced.
- Check the target size: if the target is far below what the document can reach, raise it slightly and compare.
- Review the before-and-after comparison to see what is being traded away.
The document will not open
Likely cause: The PDF may be password-protected, or the file may be incomplete or corrupted.
What to try
- According to the product description, password-protected PDFs are reported straight away rather than failing silently — check the message the app shows.
- If the file is protected, remove the password in the app that created it, then try again.
- If the file came from a download or an email, re-download or re-send it to rule out an incomplete transfer.
A scanned PDF cannot be searched
Likely cause: A scanned PDF contains page images, not text, so there is nothing for search to match until OCR has run.
What to try
- Open the document in PDF JustFit — scanned pages are OCR-recognised automatically.
- Once OCR has run, the content can be searched, extracted as text, or queried with AI chat.
- If recognition looks poor, check the scan quality: skewed or very low-resolution pages are harder to recognise.
AI chat is not available
Likely cause: AI document chat needs the on-device model, which is downloaded once.
What to try
- Download the recommended on-device model — about 1 GB — one time.
- After the model is available on the device, AI chat works without an internet connection.
- Make sure the device has enough free storage for the model download.
A PDF is already small enough
Likely cause: PDF JustFit targets the size you enter, and does not inflate a file that is already optimised.
What to try
- According to the product description, if a PDF is already fully optimised, your original file is kept rather than producing something larger.
- This is expected behaviour, not an error.
Compressing a very large scan is slow
Likely cause: Very large scanned documents are processed page by page so that memory stays under control on a phone or tablet.
What to try
- This is deliberate: it prevents a large scan from exhausting memory.
- Let the process finish rather than closing the app.
- For a very large document, consider whether you need every page before compressing.
Before you contact support
- Check the product facts page to confirm the requirement you are hitting.
- Check whether the file is a scan — scans behave differently from digital PDFs.
- Check whether AI chat has been set up, which needs the one-time model download.
- Check the App Store listing for the current version of PDF JustFit: Compress, AI Chat.
Frequently asked questions
Why is my compressed PDF still large?
Scanned and image-heavy documents have a limit on how small they can get without visible quality loss. Try Maximum compression or the Extreme preset, and compare the before-and-after result.
What happens with a password-protected PDF?
According to the product description, password-protected PDFs are reported straight away instead of failing silently.
Why did PDF JustFit keep my original file?
If a PDF is already fully optimised, PDF JustFit keeps your original file rather than producing something larger.
Where can I get more help?
See the FAQ and product facts pages on this site, and the App Store listing for the current version and support information.
Sources
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