Comparison

Chapters vs Lumen

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

Head to head
About

Chapters

A private journaling app that requires no account and keeps your entries secure. Access all your past notes anytime, synced across all your iOS devices via iCloud.

Highlights
  • Private journaling
  • No account required
  • iCloud syncing
  • Cross-device access
  • Secure entries
Features
Read full description

Chapters is your safe space to express yourself freely. No account is required, there are no in-app purchases, and your entries stay private – we never analyze or track what you write. Whether you're writing a personal journal or taking notes in class, you can access all your past notes at any time, like turning pages in your notebook. Moreover, all your entries are synced to iCloud, allowing you to access them from any iOS device.

About

Lumen

This app acts as a browser that remembers what you read, building a personal knowledge base from engaged pages. It allows you to ask questions in plain English about your reading history, with answers generated by an on-device AI. All your data remains private and offline.

Highlights
  • On-device AI knowledge base
  • Plain English questioning
  • Automatic content organization
  • Private and offline browsing
  • Tracker blocking
  • Source citation for answers
Read full description

Lumen is a browser with a memory. Most browsers forget the second you close a tab. Lumen does not. As you read, it quietly builds a personal knowledge base from the pages you actually engage with, and then lets you ask questions about any of it in plain English, answered by an AI model that runs entirely on your device. Nothing you read, nothing you ask, and nothing Lumen learns about you ever leaves your phone. WHAT IT DOES Lumen reads along with you. It distinguishes between pages you genuinely read and pages you opened and swiped away, and it extracts the meaningful content from the ones that stuck. That content gets summarized, embedded, and organized into a searchable knowledge base, all on-device. Later, when you want to find something, you do not have to dig through history or remember which tab it was in. You just ask: "What did I read about sourdough starters last week?" "Summarize that article about the new M-series chips." "What were the main arguments in that piece I read on Tuesday?" Every answer cites the pages it came from, so you can jump straight back to the source. AUTO-ORGANIZED Your reading sorts itself into a clean hierarchy: Topics, Websites, and Pages. Each level carries its own AI-generated summary, so you can scan what you have been learning at a glance. No tagging, no folders to maintain. Lumen handles it in the background. PRIVATE BY DEFAULT Lumen has no server. There is quite literally nothing to send. On-device LLM: a quantized Llama 3.2 model runs locally through Apple's MLX framework. Local SQLite storage: your reading history, summaries, and embeddings never leave the device. Built-in privacy: tracker blocking, third-party cookie blocking, and fingerprint resistance. Secure: HTTPS-only by default, with mixed-content blocking. No strings attached: no accounts, no sync, no telemetry, no ads. The AI weights download once on first launch (~700 MB). After that, everything works fully offline: browsing, reading, asking, answering. BUILT FOR iOS Lumen is written from scratch in Swift and SwiftUI, designed specifically for iPhone and iPad. It uses Apple's own frameworks wherever it can: NLEmbedding for semantic search, WKWebView for browsing, SQLite with FTS5 for full-text queries, and MLX Swift for on-device inference. Zero third-party trackers. Zero external services. WHO IT'S FOR While most browsers treat the web as a feed to scroll past, Lumen treats it as a library worth keeping. If you read a lot online and constantly think "I know I saw something about this recently but I cannot find it again," Lumen is for you. Researchers, students, writers, developers, and lifelong learners. You do not need to change how you browse. Browse normally, and Lumen takes care of the rest. REQUIREMENTS iOS 18 or later. iPhone with Apple Silicon recommended for the fastest on-device AI performance.

Screenshots

Chapters4 screens
Lumen4 screens

Verdict

The call

The clearest difference is price: Lumen at Free against Chapters's $2.99. Lumen also leads on rating (5.0 vs 4.0) and ratings volume (4 vs 1). Chapters's advantage is iOS requirement (16.0 vs 18.0). On update cadence, ads, in-app purchases and device support 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

Lumen is free to download; Chapters costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Lumen holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

UpkeepUpdate frequency

Chapters ships an update every 10 days, Lumen every 2 weeks. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.

Scorecard5 real differences · 5 level
Chapters versus Lumen: the parameters behind the verdict, then further details
ParameterChaptersLumen
Price$2.99Free — better
Rating4.0 (1 ratings)5.0 (4 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings14 — better
Update frequencyEvery 10 days — betterEvery 2 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
DevicesiPhone, iPad — betteriPhone
Requires iOS16.0 — better18.0
Further details — not scored
Size1 MB28 MB
Age rating4+17+
DeveloperStanislav StasiukDaniel Kosukhin

Customer experience

Chapters

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Lumen

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Chapters

No in-app purchases

None

Lumen

No in-app purchases

Questions

Is Chapters free?
Chapters costs $2.99, with no in-app purchases.
Is Lumen free?
Lumen is free to download, with no in-app purchases.
Which has better reviews, Chapters or Lumen?
Lumen is rated higher. Chapters averages 4.0 out of 5 from 1 ratings, while Lumen averages 5.0 from 4 ratings.
Do Chapters or Lumen have ads?
Neither Chapters nor Lumen shows ads.
Which is updated more often, Chapters or Lumen?
Chapters ships an update every 10 days, and Lumen every 2 weeks. Most recently, Chapters was updated on November 3, 2026 and Lumen on November 5, 2026.

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