Comparison

PDF vs 100 Notes Studio

Price, ratings, monetisation and update history for both apps, side by side โ€” with what reviewers say about each.

Head to head
About

PDF

Features
Read full description

Scan, edit, sign and OCR PDFs on your iPhone. Your files never leave the device. PDF-PRO is a private, offline PDF editor and scanner for contracts, invoices, receipts and everyday documents. Read, scan and annotate for free. Upgrade to Pro for unlimited merge, split, compress, OCR, signatures, watermarks and password protection โ€” the yearly plan includes a 3-day free trial. WHY PEOPLE SWITCH โ€ข Sign a contract without printing it โ€ข Scan paper and photos into a clean PDF โ€ข Merge, split or reorder pages before you send โ€ข Compress a large file so it fits in email or chat โ€ข Extract text with on-device OCR โ€ข Lock a PDF with a password, or add a watermark READ & ANNOTATE โ€ข Smooth reader with continuous scroll, pinch-to-zoom and single-page mode โ€ข Highlight, underline, strikeout, freehand ink and text notes โ€ข Search inside the document and jump to a page SCAN & CONVERT โ€ข Camera scan for paper documents, invoices and receipts โ€ข Photos to A4 PDF, or export pages as images ORGANIZE โ€ข Merge PDFs, split by page range, drag to reorder, rotate or delete pages โ€ข Folders, favorites and search in your on-device library OCR โ€ข Recognize text on the current page or the whole file โ€ข Copy or share the result โ€” processed on your iPhone, not a server SIGN & PROTECT โ€ข Handwritten signature stamp you can place and resize โ€ข PDF password and a diagonal copyright watermark PRIVACY Every merge, split, compress, OCR and encrypt step runs locally. No account. No cloud upload. FREE vs PRO Free: read, scan and basic annotation. Pro: unlimited signature, OCR, compress, password, watermark, merge and split. โ€ข Yearly โ€” best value, 3-day free trial โ€ข Monthly โ€” month to month โ€ข Lifetime โ€” pay once Subscriptions renew unless you cancel at least 24 hours before the period ends. Manage in Apple ID settings. Terms of Service (Apple EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

100 Notes Studio

Features
Read full description

Optimized for iPhone Duo. Built with the latest SDK, the app fills the entire inner display and automatically adjusts its layout whether the device is folded or open. Handwrite notes that feel like pen on paper: 29 pens and brushes, from fountain pen and pencil to fude brush and watercolor, and your handwriting is searchable later. Mark up lecture PDFs, record audio right on the page you are writing, then review with flashcards and spaced repetition. Choose from 100 notebook styles. Core editing works offline. WRITE WITH CHARACTER 29 distinct pens and brushes โ€” fountain pen, calligraphy, fude brush, technical pen, watercolor wash, charcoal, mechanical pencil (2B/4B/6B) and more โ€” each with its own texture and stroke response. Pressure and tilt shape supported strokes, while palm rejection helps prevent stray marks. Pixel, whole-stroke, and precision erasers handle corrections. Use the lasso to move, scale, copy, or delete strokes, plus a ruler, eight shape tools, and a laser pointer for presentations. 100 DISTINCT NOTEBOOK STYLES Each Studio Style has its own cover, paper structure, color palette, dividers, stamps or stickers, toolbar accent, and widget appearance. The collection includes minimal, linen, Japanese grid, academic, engineering, music, meeting, research, planner, travel, wellness, recipe, creative, and dark-paper systems. Browse and preview all 100 styles before choosing one. MORE THAN A CANVAS Fixed pages or an infinite canvas, with A4, A5, Letter, screen, and custom sizes in portrait or landscape Formatted text with bold, italic, underline, fonts, colors, lists, checklists, tables, and links PDF import and markup with highlights, underlines, strike-through, text notes, handwriting, rotation, cropping, page insertion, extraction, merging, and export Audio recordings attached to the page you choose On-device handwriting and PDF text recognition, with search across titles, body text, handwriting, and attachments Study tools with linked flashcards, cloze cards, and FSRS spaced repetition Stickers, washi tape, and an auto-numbered table of contents Nested folders, tags, pins, favorites, archives, recoverable trash, and restorable page history Ink layers with opacity, visibility, and locking, plus a reference view that keeps a PDF or image beside the page Widgets and quick capture for faster access PRIVATE BY DESIGN No account, ads, third-party tracking or analytics, and no external AI. Editing, search, and study work offline. Notes stay on your device unless you choose to export or back them up. Lock the workspace or an individual notebook with device authentication. FREE CORE, OPTIONAL ONE-TIME UPGRADE The free version includes the core editor, 29 writing tools, PDF markup, page audio attachments, handwriting search, and study tools, with 1 active notebook of up to 5 pages and 2 of the 100 styles. An optional one-time upgrade adds unlimited notebooks and pages, all 100 styles, vector-ink PDF export, restorable page history, and encrypted backup. A focused home for handwriting, documents, and study. Privacy Policy https://alice51849.github.io/100notes-support/privacy.html Terms of Use https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

PDF4 screens
100 Notes Studio4 screens

Verdict

The call

The clearest difference is update cadence: 100 Notes Studio at every 2 days against PDF's every 3 weeks. On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. PDF sells 3 in-app purchases, starting at $3.99 per month and 100 Notes Studio sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

PDF ships an update every 3 weeks, 100 Notes Studio every 2 days. The most recent releases landed on October 31, 2026 and November 8, 2026 respectively.

Scorecard1 real difference ยท 5 level
PDF versus 100 Notes Studio: the parameters behind the verdict, then further details
ParameterPDF100 Notes Studio
PriceFreeFree
Update frequencyEvery 3 weeksEvery 2 days โ€” better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPadiPhone, iPad, Apple Watch โ€” better
Requires iOS17.017.0
Further details โ€” not scored
Size12 MB19 MB
Age rating17+4+
Developer็ˆฑๅŽ ๅˆ˜Guan Feng Lai

In-app purchases

3 purchases

PDF

Subscriptions2
  • PDF-PRO Monthly$3.991 Month
  • PDF-PRO Yearly (3-Day Trial)3 Days trial$24.991 Year
One-time1
  • PDF-PRO Lifetime Pass$59.99
1 purchases

100 Notes Studio

One-time1
  • Lifetime Studio$5.99

Questions

Is PDF free?
PDF is free to download, with in-app purchases available.
Is 100 Notes Studio free?
100 Notes Studio is free to download, with in-app purchases available.
Do PDF or 100 Notes Studio have ads?
Neither PDF nor 100 Notes Studio shows ads.
Which is updated more often, PDF or 100 Notes Studio?
PDF ships an update every 3 weeks, and 100 Notes Studio every 2 days. Most recently, PDF was updated on October 31, 2026 and 100 Notes Studio on November 8, 2026.

Other comparisons