SpeederReader — Features

Speed Reading (RSVP)

Rapid Serial Visual Presentation flashes words one at a time at a fixed position on screen. Your eyes stay still, eliminating the back-and-forth saccades that slow traditional reading. Most people can comfortably reach 2–3× their normal pace within a few sessions.

Speed range: 50–750 WPM Default: 250 WPM Controls: −25 / +25 WPM buttons, always visible while reading


Optimal Recognition Point (ORP)

Each word is split at its optimal recognition point — the letter your brain uses as an anchor when reading. For odd-length words this is the exact middle letter; for even-length words it is the left-of-center letter. That letter is highlighted in gold and aligned to the horizontal screen center so your gaze never shifts.


Flow Mode

Natural reading is not metronomic — your brain needs extra time at punctuation boundaries and for long, complex words. Flow mode adjusts each word's display duration dynamically. Toggle on/off from the speed controls bar. On by default.

Algorithm

Every word starts from a baseDelay derived from your WPM setting:

baseDelay = round(60,000 ms / wpm)

Two factors can extend that delay:

  1. Punctuation pause — if the word contains any of . , ! ? ; : - – —, the minimum multiplier is raised to 2.0× (a full extra base-duration pause).
  2. Length bonus — words longer than 8 characters add +10% per extra character: lengthBonus = max(0, length − 8) × 0.1.

These are combined and capped at 2.5×:

multiplier = min(2.5, max(punctMultiplier, 1 + lengthBonus))
delay      = round(baseDelay × multiplier)

Where punctMultiplier is 2 if the word contains punctuation, otherwise 1.

Examples at 250 WPM (baseDelay = 240 ms)

Word Punctuation Length bonus Multiplier Delay
the 0 1.0× 240 ms
reading, 0 2.0× 480 ms
extraordinary (14−8)×0.1 = 0.6 1.6× 384 ms
unfortunately, (15−8)×0.1 = 0.7 2.0× (punct wins) 480 ms
internationally, (17−8)×0.1 = 0.9 2.5× (capped) 600 ms

Context Strip

A paragraph-level view sits above the RSVP word display, showing the surrounding text with the current word highlighted. This keeps you oriented in the narrative and helps comprehension — you always know where you are in the sentence.


Word Navigation

When paused, left and right arrow buttons appear below the context strip so you can step forward or backward one word at a time. Useful for re-reading a confusing phrase or reviewing what you just read.


Dictionary Lookup

Tap look up word when paused to look up the current word on Dictionary.com:


Progress Saving

Your reading position is saved automatically whenever you turn a page, pause, or jump. When you reopen a file, SpeederReader offers to resume from where you left off. Progress is stored locally on-device — no account required.


Page Jumping

Tap the page indicator in the bottom bar to jump to any page. Jumping saves progress and auto-resumes reading.


Project Gutenberg Browser

Search and load any of the 70,000+ free books from Project Gutenberg directly inside the app — no file download required. Results show title, author, download count, and available format. Books open in the best available format (EPUB preferred, falling back to plain text).


Light & Dark Mode

SpeederReader supports both a light and a dark theme, optimized for different reading environments.

Theme Best for
Light — warm cream background, dark brown text Daytime, bright rooms, outdoor reading
Dark — near-black background, soft cream text Night reading, low-light environments, reducing eye strain

Toggle the theme at any time with the Light / Dark button:

Your preference is saved locally and persists across sessions. On first launch, SpeederReader matches your device or browser system theme (dark or light).

The gold ORP highlight (#C8A951) and accent color remain consistent in both modes for visual continuity.


Continue Reading

When you open a book, SpeederReader saves it locally so you can pick up where you left off — even after closing the app. The home screen shows a Continue Reading card with the book title and a play button. Your reading position and WPM setting are preserved between sessions. Dismiss the card with to clear the saved book.


OpenDyslexic Font

SpeederReader includes OpenDyslexic, a typeface designed to increase readability for readers with dyslexia. Toggle it with the Dyslexic button:

When active, all text switches to OpenDyslexic with slightly smaller font sizes optimized for the wider letterforms. Your preference is saved locally and persists across sessions.


Persistent WPM

Your reading speed setting is saved automatically whenever you adjust it — on the home screen or in the reader. When you return to SpeederReader, it remembers your preferred WPM instead of defaulting to 250.


Localization (English & Spanish)

The full UI is available in English and Spanish. Language is detected automatically from your device or browser settings on first launch. You can switch languages at any time with the EN / ES toggle in the top-right corner of the home screen. Your preference is saved locally and persists across sessions.

Localized strings cover all screens: home screen controls, progress indicators, reader overlays, modal dialogs, and the finished screen.


Supported Formats

Format Notes
PDF Parsed via PDF.js (on-device)
EPUB Parsed via JSZip; each chapter = one page
HTML Parsed directly in JS
Markdown Parsed directly in JS
Plain text Parsed directly in JS

All parsing is 100% on-device. Your files are never uploaded anywhere.