PDF Expert vs Skim (2026): which should you pick?
As of Nov 13, 2026, Skim grades higher than PDF Expert: 2.8 against 2.4 out of 4.0.
Checked Nov 9, 2026 and Nov 13, 2026 · graded Nov 9, 2026 and Nov 13, 2026 by ToolGPA
PDF Expert grades higher on platforms. Skim grades higher on value for money and the free plan. They get the same grade on features and ease of use.
Price, platforms and features side by side. The table says where each price was read and when.
PDF Expert
PDF reader and editor for Mac, iPhone and iPad from Readdle
Which one is for you
Pick PDF Expert if
- Fits if you work on a Mac and an iPad and want one $79.99 subscription for both
- Works for students who mostly read, highlight and sign, on the free app
Look elsewhere if
- Skip it if you or your team use Windows, Android or a browser at all, as it's Apple only
- Not for you if you build fillable forms or send for signature, as neither is on record
- Tight if you need OCR on an iPhone or iPad, as it's listed for the Mac
- Watch out: the free app won't edit, convert or merge, and the Premium trial is a week, through the App Store
- Watch out: the student discount is 30% in one place and 50% in another, and the $139.99 Lifetime license is Mac only, with new features possibly extra
Pick Skim if
- Fits if you read and mark up papers on a Mac, especially with LaTeX or BibDesk
- Works for anyone who wants a free annotator and not an editor
Look elsewhere if
- Skip it if you use Windows, Linux or a phone, as it runs on Mac only
- Too light for editing text or filling in forms, since neither is listed
- Watch out: support is a wiki, mailing lists and bug trackers, not a help desk
- Tight if your Mac is old, because the current version needs macOS 10.13
How we grade them
| 2.4GPAPDF ExpertFair | 2.8GPASkimGood | |
|---|---|---|
| Value for money | BPremium is $79.99 a year and covers your Mac, iPhone and iPad in one go, right in the middle of what PDF editors charge. A Lifetime license is $139.99 once, under two years of the category's middle subscription, but it covers the Mac version only. Business is $80 a seat a year. | AFree to download and use, with no paid tier, so it sits well under the cheapest quarter of PDF tools. |
| Free plan and trial | CThe free app reads, highlights, adds notes, and fills and signs forms. But editing text, converting, merging and the AI all need Premium. The 1-week trial runs through the App Store. | AThe whole app is free, with nothing held back. |
| Features | CEdits text like a word processor, converts to Office, merges, compresses, redacts and measures drawings, with an AI assistant. The gaps: OCR is listed for the Mac only, and there's no form builder or sending for signature on record. | CNotes, highlights, snapshots, a reading bar and AppleScript. It does that job fully, but it is a smaller one: the listing shows no text editing or form filling. |
| Ease of use | B4.67 from 216,183 App Store ratings, a whisker off the top grade. It's an app you open and use, and it's made for marking up with an Apple Pencil on an iPad. | BNo store rating is on record, but it is a program you install and open, with nothing to set up. |
| Platforms and integrations | CMac, iPhone and iPad only. No Windows, no Android, no browser version, and no integrations on record. If you're not all on Apple, it's no use. | DmacOS only, version 1.7.19 needing macOS 10.13 or higher. There is no Windows, phone or web version. |
| Best for | PDF editing across a Mac, iPad and iPhone | reading and annotating papers on a Mac |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: PDF Expert and Skim. How we grade
Price against what you get
PDF Expert starts at $6.67 a month when paid by the year and scores 2.3 out of 4 on features, ease of use and platforms. Skim has no paid plan and scores 2.0.
PDF Expert scores higher, and starts $6.67 a month higher: the question is whether the extra is worth that to you. Of the other PDF editors on the chart, 9 score higher than PDF Expert for less, and none scores higher than Skim for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Skim is open source, according to its own site.
- PDF Expert also covers forms.
- Skim also covers notes and highlights.
At a glance
| PDF Expert | Skim | |
|---|---|---|
| Pricing | Free plan | Free |
| Starts at | $79.99 per year | Free |
| Free plan | The free app reads PDFs, highlights and marks them up, adds notes and stamps, and fills and signs forms; editing, converting and AI need Premium. | Everything: the whole app is free to download and use. |
| Free trial | 1-week free trial of Premium through the App Store | None listed |
| macOS | ||
| iOS | ||
| Made by | Readdle | Skim project (SourceForge) |
| Price read from | pdfexpert.com | skim-app.sourceforge.io |
| Checked | Nov 9, 2026 | Nov 13, 2026 |
Worth knowing
PDF Expert
- Runs on Apple devices only: there is no Windows, Android or browser version.
- Editing, converting, merging, compressing, redaction and PDF Copilot all need Premium; the free app reads, annotates and signs.
- The education discount is stated as 30% off the annual plan in one place on the pricing page and as 50% in another.
- The $139.99 lifetime license covers the Mac version only; new features may cost extra, and Premium on iPhone and iPad still needs the yearly plan.
Skim
- Mac only; current version 1.7.19 needs macOS 10.13 or higher, with older versions listed for older systems.
- It is a reader and annotator, with no listed tools for editing existing text or filling in forms.
- Support runs through a wiki, mailing lists and bug trackers rather than a company help desk.
Key features
PDF Expert
- Text and image editing
- Premium edits text in a PDF much like a word processor, adds, replaces and resizes images, and adds links and outlines.
- Convert, merge and compress
- Creates PDFs from Word files and images, converts PDFs to Word, Excel, PowerPoint, images and text, and merges, splits and shrinks files.
- Annotate, fill and sign
- Highlight, draw, add notes, stamps and audio notes, and fill and sign forms, including AcroForms and static XFA forms, in the free app.
- PDF Copilot
- Premium's AI assistant lists main points, summarizes, answers questions with references and explains words or phrases in a document.
- OCR and scan clean-up
- Recognizes text in scanned documents on Mac, and an AI Enhance feature removes shadows and distortion from scans.
- Measuring and redaction
- Scale and measure drawings with polygon, polyline and redline tools, and permanently black out sensitive text.
Skim
- Notes and highlights
- Add and edit notes, highlight text with one-swipe modes, and view all notes and highlights in one list.
- Snapshots and reading bar
- Keep snapshots of other parts of a document for reference and focus a line at a time with a reading bar.
- Navigation
- Move around with the table of contents or thumbnails, with a visual history and previews of internal links.
- Presentations
- Present a PDF full screen with built-in transitions, and crop pages with the smart cropping tools.
- Export and scripting
- Export notes as text and automate with extensive AppleScript support.
- LaTeX and reference tools
- Works with LaTeX through SyncTeX and PDFSync, and integrates with BibDesk and other third-party apps.
Plans
PDF Expert
Free$0
Read, annotate, fill and sign PDFs on Mac, iPhone and iPad.
Premium$79.99
per year
Edit text, images and links, convert, OCR, merge and compress, redact, translate and PDF Copilot, on iPhone, iPad and Mac, with a 30-day money-back guarantee.
Business$80
per seat / year, before tax
Premium for teams bought online, each seat covering up to 3 devices, with a Business Manager to add, remove and reassign seats.
Lifetime$139.99
one-time
The Premium features for the Mac version only, paid once with a 30-day money-back guarantee; later new features may cost extra.
Skim
Skim$0
Free to download; the site lists no paid plans or licence fees.
Ways to pay less
PDF Expert
- Lifetime license
Lifetime Mac license for $139.99
A one-time payment of $139.99 buys the Mac version for good, with bug fixes and support; Readdle says new features may come at extra cost.
- Education
Discount for students and educators
Verifying a school email on the pricing page sends a discount on the annual plan, given there as 30% and also as 50%; the App Store lists an education purchase at $39.99.
Skim
No public discounts listed.
Common questions
Which is cheaper, PDF Expert or Skim?
As of Nov 13, 2026, Skim is cheaper to start with: it is free, against $6.67 a month when paid by the year for PDF Expert. PDF Expert starts at $79.99 per year, and Skim is free.
Which has a free plan, PDF Expert or Skim?
As of Nov 13, 2026, both PDF Expert and Skim have a free plan.
Which platforms do PDF Expert and Skim run on?
As of Nov 13, 2026, only PDF Expert lists an iOS app. Both list a macOS app. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.