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.
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 on iPhone, iPad, and Mac, and pick up on any of them at the word you stopped on. No ads, no subscription, no account.
Live demo — hold to read
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.
Each word arrives at the same focal point, so your eyes can stay with the text.
Words change. Your focal point does not.
Hold, drag, search, change chapters, and resume without losing your position in the document.
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.
Strobe aligns each word on a highlighted letter at a fixed position on the screen, in the highlight color you choose.
Choose timing adjustments for word length, punctuation, sentence endings, and word complexity.
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.
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.
Import a PDF, EPUB, TXT, or Markdown file, paste text, or share an article from Safari to Strobe.
Choose your reading speed, font, text size, highlight color, and Smart Timing preferences.
Hold to read, or tap with two fingers to read hands-free. Strobe saves your place, and iCloud Sync can carry it to your other devices.
Import a document or paste text to add it to your reading library.
Read papers section by section, and search the full passage to revisit a definition or result.
Import assigned chapters and PDFs, adjust the pace, and return to your saved position.
Share articles from Safari, import essays, reports, and manuscripts, or paste text into your library.
Strobe processes imported documents on your device and has no server of its own. Turn on iCloud Sync, and your library and reading positions 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.
RSVP, ORP, and document-reading techniques explained in plain language.
How one-word presentation works, how to set the pace, and how to use passage view.
02 PDF reading · 1 minA repeatable process for research papers, reports, and long documents.
03 Word alignment · 2 minHow Strobe chooses a highlighted letter and aligns words around it.
Strobe’s source is public. Inspect how documents are handled, report an issue, request a feature, or build on the project.
View source on GitHubAn RSVP reader displays text one word or phrase at a time at a fixed position, with an adjustable presentation speed.
Yes. Strobe is free to download, with no subscription, in-app purchases, or ads, and its source code is public. No account is required.
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.
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. If you turn on iCloud Sync, your library and reading positions are stored in your private iCloud account, which the developer cannot access.
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.
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.
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.
Yes. With iCloud Sync on, your library and reading positions 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. Display and timing settings stay on each device.
The reading speed is adjustable from 100 to 1,000 words per minute. You can change WPM before reading or drag vertically while reading to tune it live.
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.
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.
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.
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.
No. WPM controls how quickly words are presented. Smart Timing and punctuation pauses can extend the time each word stays on screen. Choose a pace you can follow, pause to check your understanding, and use passage view to reread difficult text.
iPhone · iPad · Mac · No ads · No account