Comparison

Mio vs MarginNote 4

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

Head to head
About

Mio

This AI-powered assistant solves math problems, plots graphs, and answers general knowledge questions directly on your device. It can process image input for homework and offers offline capabilities for most functions, only connecting online for live data.

Highlights
  • AI math problem solving
  • Real-time graph plotting
  • Image input for homework
  • Offline knowledge assistant
  • Live data retrieval
  • General knowledge inquiries
Features
Read full description

Mio is your all-in-one AI math and knowledge assistant, running completely on your iPhone and iPad. Mio is powered by a proprietary computer algebra system, and can answer math questions, solve equations, and plot graphs in real time faster than any other AI assistant on the App Store! And now, when Mio needs a little extra help, it can use Apple's Foundation Language Models (available starting with iOS 26) right on your device! No internet connection required. Mio only connects online when you ask for live data such as currency exchange rates or weather conditions. Everything else, including nutrition data, is processed completely on your device. With Mio, you can even use image input to snap photos of your homework with no limit. But Mio doesn't stop at math alone. Wondering about the weather or need quick facts? Just ask! Mio's capabilities extend beyond equations, making it a versatile tool for all sorts of inquiries. Embrace the power of instant answers and unlock a world of knowledge with Mio on your iPhone and iPad.

About

MarginNote 4

This app integrates reading, note-taking, mind mapping, and flashcards into a unified study environment. It supports active learning with features like study sets, book compilation, and dual-article views. Enhance your understanding with visual learning tools and AI-powered content extraction for long-term memory retention.

Highlights
  • Integrated reading, note-taking, mind mapping, and flashcards
  • Quick Extend Note and Handwriting Layers for annotation
  • Study Set for organizing PDFs, EPUBs, videos, and audio
  • Mind Map and Concept Diagram for visual learning
  • AI Content Detection for formula and chart extraction
  • FSRS spaced-repetition algorithm for reviews
  • iCloud sync across Apple devices
Features
Read full description

MarginNote is the PDF study tool for deep readers. One excerpt is a PDF highlight, a mind map node, and a flashcard — one capture, three places. This is the Card Axis architecture, so you stop ferrying content between a PDF reader, a notes app, and a flashcard tool. A decade of iteration. 188K+ App Store ratings. 【Four Featured Mechanics】 ▸ Card Axis — One excerpt, three renders. Document highlight, mind map node, and flashcard are the same card seen from three angles. ▸ Title Link — Old notes auto-surface in new documents. When a familiar concept appears in what you're reading, your past annotation lights up on the page. ▸ Extended Note — Long-press anywhere on a PDF to open writing space. No anchored text required; three display modes (inline / margin / collapsed). ▸ Immersive Mode (4.4) — Three-state toggle: Read / Write / Recall. UI folds away. Recall blurs excerpts with Gaussian blur — tap to reveal only after you've actually recalled. 【AI Capabilities (introduced in 4.2)】 AI book breakdown · AI OCR templates · AI translation · AI Q&A · AI flashcard generation Our stance is AI as assistant, not replacement — every suggestion can be saved as your own thinking node, never thinking for you. 【Apple Intelligence (iOS 26+)】 Recall Mode hints can run on-device via Apple Intelligence — pick "Apple AI" or "cloud LLM" in Settings. With Apple AI selected, three tiers of help — Neighbor Coordinate · Reasoning Prompt · Key Distinction — are generated by Apple Foundation Models right on your device: no network calls, no AI credits used, your notes never leave your device. Even if you've selected cloud LLM, going offline auto-falls back to Apple Intelligence (provided your device supports it) — so libraries, planes, and exam-day silent rooms never break your hint loop. 【Full Workflow】 Fast OCR · Study Sets (PDF / EPUB / video / audio) · direct read from Zotero / cloud drives / USB · 10 mind map styles · book recomposition · dual-document compare · concept maps · handwriting layers 【FSRS Spaced Repetition】 Built on the open-spaced-repetition project's algorithm (paper accepted by ACM SIGKDD; Anki has used FSRS as its default scheduler since v23.10). Push short-term memory into long-term. 【Built For】 Anyone re-reading a single document until it sticks — med school (USMLE / MCAT) · law school (LSAT / bar exam) · grad prep (GRE / GMAT / CFA) · researchers · language learners (IELTS / TOEFL) · serious readers. 【All Apple Platforms】 iPhone + iPad + Mac under one Apple ID. iCloud syncs Study Sets, notes, and review progress. Native Apple Pencil support on iPad. — Questions? Email service@marginnote.com Terms: https://dist.marginnote.com/MarginNote_Terms_and_Conditions.pdf Privacy: https://dist.marginnote.com/MarginNote_Privacy_Policy.pdf

Screenshots

Mio4 screens
MarginNote 44 screens

Verdict

The call

The clearest difference is in-app purchases: Mio at none against MarginNote 4's 13. MarginNote 4's advantage is ratings volume (736 vs 75) and iOS requirement (17.0 vs 26.0). On price, rating, review sentiment and update cadence there is nothing between them.

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. MarginNote 4 sells 12 in-app purchases, starting at $1.99 per month. Mio asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.5 for Mio against 4.5 for MarginNote 4. That said, the two scores are not equally well evidenced: MarginNote 4 has 736 ratings behind it against 75, so its average is the more settled of the two. Written reviews are what separate them: 51% of Mio's written reviews are positive against 58% of MarginNote 4's.

UpkeepUpdate frequency

Mio ships an update monthly, MarginNote 4 every 3 weeks. The most recent releases landed on October 17, 2026 and October 22, 2026 respectively.

Scorecard4 real differences · 6 level
Mio versus MarginNote 4: the parameters behind the verdict, then further details
ParameterMioMarginNote 4
PriceFreeFree
Rating4.5 (75 ratings) — better4.5 (736 ratings)
Positive reviews51.1% of reviews58.5% of reviews — better
Number of ratings75736 — better
Update frequencyMonthlyEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, Mac — better
Requires iOS26.017.0 — better
Further details — not scored
Size11 MB330 MB
Age rating4+4+
DeveloperPomegranate Apps LLCBeijing Yunsi Software Technology Co., Ltd

Customer experience

Mio

All ratings75 ratings
Positive86.7%
Neutral5.3%
Negative8.0%
Written reviews45 reviews
Positive51.1%
Neutral11.1%
Negative37.8%

MarginNote 4

All ratings716 ratings
Positive86.3%
Neutral3.6%
Negative10.1%
Written reviews566 reviews
Positive58.5%
Neutral15.5%
Negative26.0%

Bugs and requests

Mio

Not enough reviews yet to summarise bugs or requests.

MarginNote 4

Reported bugs

3 issues
  • Disappearing annotations when using extend function
  • Inability to restore accidentally deleted mind maps
  • Inconsistent behavior with PDF file management

Requested features

4 requests
  • Improved iCloud/cloud sync reliability
  • More intuitive and user-friendly interface
  • Better support for external document libraries
  • Ability to disable auto-excerpt selection

In-app purchases

None

Mio

No in-app purchases

12 purchases

MarginNote 4

Subscriptions5
  • Subscription to MAX (Monthly)7 Days trial$1.991 Month
  • Subscription to MAX (3 months)7 Days trial$4.993 Months
  • Subscription to MAX (6 months)7 Days trial$7.996 Months
Show 2 more
  • Subscription to MAX (Annually)1 Month trial$12.991 Year
  • MarginNote Max Annual1 Month trial$16.991 Year
One-time7
  • 14 days Free Trial2 variantsFree
  • Upgrade to PRO from MN3(iOS)$4.99
  • Unlock PRO Forever (New)$12.99
Show 4 more
  • Upgrade to MAX from MN3(macOS)$19.99
  • Unlock MAX based on PRO$39.99
  • Unlock MAX based on PRO (New)$40.00
  • Unlock MAX Forever (New)$51.99

Questions

Is Mio free?
Mio is free to download, with no in-app purchases.
Is MarginNote 4 free?
MarginNote 4 is free to download, with in-app purchases available.
Which has better reviews, Mio or MarginNote 4?
Mio is rated higher. Mio averages 4.5 out of 5 from 75 ratings, while MarginNote 4 averages 4.5 from 736 ratings.
Do Mio or MarginNote 4 have ads?
Neither Mio nor MarginNote 4 shows ads.
Which is updated more often, Mio or MarginNote 4?
Mio ships an update monthly, and MarginNote 4 every 3 weeks. Most recently, Mio was updated on October 17, 2026 and MarginNote 4 on October 22, 2026.

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