01 Control100–1,000 WPM
Adjust the pace as you read.
Hold to read and release to pause, or tap with two fingers to read hands-free. Drag up or down mid-read to tune speed without opening a menu or losing your place.
Free & open sourceFree RSVP speed reading app for iPhone, iPad & MacRead more.
Free RSVP speed reading app for iPhone, iPad & MacRead more.
Move less.
Strobe is a free, open-source RSVP speed reader for your own PDFs, EPUBs, and web articles. Read one word at a time at 100–1,000 WPM, or listen as an on-device voice reads along, on iPhone, iPad, and Mac, and pick up on any of them at the word you stopped on. No ads, no subscription, no account.
iPhoneiPadMac100–1,000 WPM
Live readerHold · Drag · Release
Live demo — hold to read
FreeNo ads or in-app purchases
6 inputsPDF, EPUB, TXT, MD, paste, web
0 dataCollected by the app
OpenSource code on GitHub
Spec sheet
Strobe at a glance
Rapid Serial Visual Presentation (RSVP) displays words one at a time at a fixed point. Strobe pairs this reading format with adjustable timing, passage search, and saved progress.
Developed by Jaafar Abdeen. Facts checked . Check compatibility on the App Store or inspect Strobe’s source code.
- Devices
- iPhone, iPad, Mac (iOS 17+, iPadOS 17+, macOS 14+)
- What it reads
- PDF, EPUB, TXT, and Markdown files (including notes from Obsidian), pasted text, and web articles shared from Safari or other apps
- Reading speed
- 100–1,000 words per minute, counting every pause, adjustable while you read
- Read aloud
- An optional on-device voice reads along at up to 450 words per minute, with 15 English voices, and keeps reading in the background on iOS 27 and Mac. It reads English documents, on iPhone and iPad models with about 4 GB of memory or more and on every Mac.
- Sync
- Optional iCloud sync of your library, reading positions, and reading history across iPhone, iPad, and Mac. Each device keeps its own copy for offline reading.
- Works with
- The share sheet, Siri, Shortcuts, Now Playing, and a Continue Reading widget for the Home Screen, Lock Screen, and Mac desktop.
- Price and privacy
- Free and open source, with no ads, subscription, or in-app purchases. No account, and no data collected by the developer.
- File limits
- DRM-protected EPUBs and password-protected PDFs cannot be imported. PDFs need a text layer. Strobe does not run OCR on scanned pages.
- Reading expectations
- A WPM setting is a presentation rate, not a guarantee of reading comprehension.
Each word arrives at the same focal point, so your eyes can stay with the text.
Words change. Your focal point does not.
02 / Features
Control how you read.
Hold, drag, listen, search, change chapters, and resume without losing your position in the document.
02 FocusORP aligned
A fixed point for every word.
Strobe aligns each word on a highlighted letter at a fixed position on the screen, in the highlight color you choose.
03 ListenOn-device voice
Listen as the words go by.
Turn on Read Aloud, and a natural voice reads along as the words show, at up to 450 WPM. It downloads once and runs on your device, with 15 English voices, and on iOS 27 and Mac it keeps reading with the screen locked or in another app.
04 PacingLocally analyzed
Adjust timing for each word.
Choose timing adjustments for word length, punctuation, sentence endings, and word complexity. Your speed still counts every pause.
05 NavigationProgress saved
Search, navigate, and resume.
Open the passage, search words or phrases, jump between matches, browse chapters, and resume from the exact word you left, on any of your devices.
06 PrivacyZero data collected
Your library, private and in sync.
Documents are processed on your device. Optional iCloud Sync carries your library and place through your own iCloud account. No Strobe account, analytics, or server.
03 / Workflow
From document to reading in three steps.
- 01
Drop it in
Import a PDF, EPUB, TXT, or Markdown file, paste text, or share an article from Safari to Strobe.
- 02
Set the rhythm
Choose your reading speed, font, text size, highlight color, and Smart Timing preferences.
- 03
Lock on
Hold to read, tap with two fingers to read hands-free, or turn on Read Aloud and listen along. Strobe saves your place, and iCloud Sync can carry it to your other devices.
- EPUB
- TXT
- Markdown
- Pasted text
- Web articles
04 / Use cases
Books, papers, and articles.
Import a document or paste text to add it to your reading library.
Research papers
Read papers section by section, and search the full passage to revisit a definition or result.
Course reading
Import assigned chapters and PDFs, adjust the pace, and return to your saved position.
Long-form backlog
Share articles from Safari, import essays, reports, and manuscripts, or paste text into your library.
05 / Private by default
Your library stays yours.
Strobe processes imported documents on your device and has no server of its own, and the voice that reads aloud runs there too. Turn on iCloud Sync, and your library, reading positions, and reading history move between your devices through your private iCloud account, which the developer cannot access. There are no Strobe accounts, analytics SDKs, ads, or tracking profiles.
- On-device processing
- Private iCloud sync
- No account
- No analytics
06 / Guides
Understand the mechanics of RSVP reading.
RSVP, ORP, and document-reading techniques explained in plain language.
01 RSVP reading · 2 min
How RSVP reading works
How one-word presentation works, how to set the pace, and how to use passage view.
02 PDF reading · 1 minRead PDFs faster without losing the thread
A repeatable process for research papers, reports, and long documents.
03 Word alignment · 2 minHow the Optimal Recognition Point works
How Strobe chooses a highlighted letter and aligns words around it.
Source available on GitHubRead the code.
Read the code.
Change the code.
Strobe’s source is public. Inspect how documents are handled, report an issue, request a feature, or build on the project.
View source on GitHub07 / FAQ
Files, privacy, pace, and access.
01What is an RSVP reader?
An RSVP reader displays text one word or phrase at a time at a fixed position, with an adjustable presentation speed.
02Is Strobe free?
Yes. Strobe is free to download, with no subscription, in-app purchases, or ads, and its source code is public. No account is required.
03Does Strobe teach speed reading?
Strobe is a reader rather than a training course, so it has no drills or tests. You import your own PDFs, EPUBs, and articles and read them with RSVP at the pace you choose.
04Does Strobe upload or collect my documents?
No. Strobe processes documents on your device and has no server of its own, and Apple’s App Store privacy label lists it as collecting no data. Read Aloud generates speech on your device, so your documents are never sent anywhere to be read. If you turn on iCloud Sync, your library, reading positions, and reading history are stored in your private iCloud account, which the developer cannot access.
05Which files can Strobe read?
Strobe imports PDF, EPUB, TXT, and Markdown files, along with pasted text and web articles from the share sheet. DRM-protected EPUB files and password-protected PDFs cannot be imported.
06Can Strobe read Markdown files and Obsidian notes?
Yes. Strobe imports Markdown files, including notes from Obsidian and other notes apps, and reads the words you would see on the rendered page. Headings become chapters, and formatting marks, link addresses, code blocks, and front matter are left out.
07Can I speed read web articles in Strobe?
Yes. In Safari on iPhone, iPad, or Mac, share an article to Strobe to add its headline and text without the page’s menus and ads, or select a passage first to add only that part. Links and text shared from other apps work too.
08Which devices does Strobe support?
Strobe runs natively on iPhone, iPad, and Mac, and adapts to both screens of iPhone Duo. It requires iOS or iPadOS 17 or later, or macOS 14 or later.
09Does Strobe sync between devices and work offline?
Yes. With iCloud Sync on, your library, reading positions, and reading history sync across iPhone, iPad, and Mac, so you can pick up at the word you stopped on. Each device keeps its own copy of your documents, so reading works offline, and so does Read Aloud once its voice is downloaded. Display and timing settings stay on each device.
10How fast can I read in Strobe?
The reading speed is adjustable from 100 to 1,000 words per minute, and up to 450 while the voice reads aloud. It counts every pause, so a document set to 300 WPM reads at 300 words per minute overall. You can change WPM before reading or drag vertically while reading to tune it live.
11Can Strobe read documents aloud?
Yes. Turn on Read Aloud with the speaker button in the reader, and a natural voice reads along as the words show, at up to 450 words per minute. The voice model downloads once, about 162 MB, and runs on your device, with 15 English voices, American and British. On iOS 27 and Mac it keeps reading with the screen locked or in another app, and you can play and pause it from Now Playing or your headphones. Read Aloud reads English documents, on iPhone and iPad models with about 4 GB of memory or more and on every Mac.
12Does Strobe track my reading?
Strobe keeps statistics on your device: time and words read, your average session, and your real reading speed, with and without the voice, by week, month, year, or all time. Open them from the Statistics button in the library. With iCloud Sync on, they include your reading on your other devices.
13What is ORP highlighting?
ORP means Optimal Recognition Point. Strobe highlights one letter slightly left of each word’s center and keeps that letter at the same spot on screen, giving your eyes a stable place to focus as words change. The highlight is red by default, and you can choose orange, green, teal, blue, purple, or pink.
14Does Strobe support hands-free and accessible reading?
Yes. Hold to read, tap with two fingers to read hands-free, or turn off Hold to Read so a single tap starts and stops reading. Strobe also supports VoiceOver, Larger Text, Reduced Motion, Dynamic Type, and keyboard controls on compatible devices.
15Does Strobe work with Siri, Shortcuts, and widgets?
Yes. Ask Siri to “Continue reading in Strobe,” open a document by name, or ask “How far am I in Strobe?” The Speed Read Text action in Shortcuts sends any text to Strobe, and the Continue Reading widget shows your current book and time left on the Home Screen, Lock Screen, or Mac desktop.
16Can Strobe read scanned PDFs?
Strobe reads a PDF’s text layer and does not run OCR. For an image-only scan, add a text layer with an OCR tool before importing. Keep the original PDF available for figures and tables.
17Does a higher WPM setting guarantee better comprehension?
No. WPM controls how quickly words are presented. Smart Timing and punctuation pauses give some words more time and others less, within the same overall speed. Choose a pace you can follow, pause to check your understanding, and use passage view to reread difficult text.
Give your eyes one place to be.
Download StrobeiPhone · iPad · Mac · No ads · No account