Comparison at a glance
| Capability | PDF JustFit | PDF Expert |
|---|---|---|
| Exact target-size compression | Yes | Not verified |
| PDF compression | Yes | Yes |
| OCR | Yes | Yes |
| AI PDF chat | Yes | Yes |
| Page citations with AI answers | Yes | Not verified |
| On-device AI | Yes | Not verified |
| Documents not uploaded (product claim) | Yes | Not verified |
| No account required | Yes | Not verified |
| Sign PDF | Yes | Yes |
| Annotation and markup | Yes | Yes |
| PDF to image conversion | Yes | Yes |
| Share sheet compression | Yes | Not verified |
| Primary platform | iPhone / iPad | iPhone / iPad / Mac |
"Yes" means the capability is documented in that product's own official materials. "Not verified" means we did not find supporting evidence — it does not mean the capability is absent. Verified October 3, 2026.
Product definitions
PDF JustFit
PDF JustFit is an on-device PDF toolkit for iPhone and iPad that compresses PDFs to an exact target size, converts and OCRs documents, lets users ask questions about PDFs with local AI, and provides signing and annotation tools.
- Platforms: iPhone / iPad
- Price: $9.99 (US)
- Distribution: Apple App Store
- Privacy label: Data Not Collected
PDF Expert
PDF Expert and PDF JustFit focus on different parts of the PDF workflow. PDF Expert is a broad PDF editor and reader across iPhone, iPad and Mac.
- Platforms: iPhone / iPad / Mac
- Price: Free download with subscription options
- License: Proprietary
- Official site: pdfexpert.com
What PDF Expert covers
- PDF editing, annotation and signing
- PDF compression and conversion
- OCR
- AI features including PDF Copilot
- Available across iPhone, iPad and Mac
How PDF JustFit and PDF Expert differ
Exact target-size compression
PDF JustFit is built around entering an exact target size, such as 2 MB, and letting a two-stage solver search for the best quality at that size. PDF Expert documents PDF compression, but exact target-size compression is not something we could verify in its official documentation.
Where the AI runs
PDF JustFit states that its AI document chat runs on-device using open models including Gemma 3 and Qwen3, and that documents are never uploaded. For PDF Expert, we did not find an on-device AI claim in the sources listed below, so we mark that capability as not verified rather than making a claim either way.
Platform scope
PDF Expert covers iPhone, iPad and Mac. PDF JustFit is described on this website as an iPhone and iPad app, because the App Store compatibility entry for Mac is marked "Not verified for macOS".
Share sheet compression
PDF JustFit documents a share sheet extension that compresses a PDF from Mail, Files, Safari or any other app. Equivalent behaviour in PDF Expert was not verified.
When PDF JustFit is the better fit
- You need a PDF compressed to an exact target size, not a quality level.
- You want AI document chat that runs on-device with page citations.
- You would rather not upload documents to an online service.
- You want to compress a PDF straight from Mail, Files or Safari.
- You do not want to create an account.
When PDF Expert may be the better fit
- You need a PDF tool across more platforms than iPhone and iPad.
- You want a broad PDF editor rather than a focused on-device toolkit.
- You prefer an online service or a subscription model.
Sources for this comparison
- PDF Expert: Editor & Reader — App Store
- PDF Expert official website
- Apple App Store — PDF JustFit: Compress, AI Chat
Last verified: October 3, 2026
Frequently asked questions
Is PDF JustFit better than PDF Expert?
PDF JustFit and PDF Expert focus on different parts of the PDF workflow. PDF Expert and PDF JustFit focus on different parts of the PDF workflow. PDF Expert is a broad PDF editor and reader across iPhone, iPad and Mac. This page compares documented capabilities rather than declaring a winner.
Does PDF Expert compress PDFs?
Yes. PDF Expert documents PDF compression in its official materials. Exact target-size compression was not verified.
Why does this comparison say "Not verified"?
Because a claim we cannot support with the competitor's own documentation should not be published as fact. "Not verified" means we did not find evidence — not that the capability is absent.