David proposed: "for sentence we can add in the red letter to keep the eye in the middle of the sentence block." Sentence mode now picks the middle word of each sentence (by word index) and applies the same ORP-character formula used in Word mode. The single red letter gives the eye a fixed anchor; the rest of the sentence is absorbed peripherally instead of saccading. This matters most at high WPM (post v1.1.1/v1.1.2 — Sentence mode now goes up to 3000 WPM with a 400ms minimum-display floor). Without an anchor, the eye scans from the left as if reading normally and runs out of time. With the anchor, the eye fixates immediately and the whole sentence registers in one peripheral-vision read. Paragraph mode still renders plain text — a single ORP on a multi-line block doesn't give a useful fixation point. Per-sentence ORP within paragraphs could come in a future release if needed.
◈ Ranger Reader
A lightweight RSVP reader for academic papers and long-form text — single HTML file, no install, no subscription, no cloud, runs offline in any browser.
Built to handle the volume of reading required by a research thesis without paying the $120/year for SwiftRead or similar tools. Released here so others can do the same.
What it does
Three reading modes for the same text:
| Mode | What it does | Best for |
|---|---|---|
Word (key 1) |
Classic RSVP — one word at a time at a chosen WPM, with ORP (Optimal Recognition Point) focal-character colouring | Fast skim, the "I'm reading at 4× normal speed" experience |
Sentence (key 2) |
One full sentence at a time, auto-advancing based on word count | Comprehension-grade reading of methods and results sections |
Paragraph (key 3) |
One paragraph at a time, longer display | Preview / postview stages, skim for quotes |
How to use
- Open
ranger-reader.htmlin any modern browser (double-click works) - Paste text into the textarea at the bottom, or drag any
.txtfile onto the page - Press the spacebar or click ▶ Play
- Tap
1/2/3to switch between Word / Sentence / Paragraph modes - Slide WPM up or down to taste (default 500, range 200–1500)
Text, WPM, mode, and reading position all auto-save in your browser — close the tab, reopen tomorrow, resume where you stopped.
Keyboard shortcuts
| Key | Action |
|---|---|
Space |
Play / pause |
← / → |
Skip back / forward (10 in Word mode, 1 in chunk modes) |
1 / 2 / 3 |
Switch to Word / Sentence / Paragraph mode |
+ / − |
Adjust WPM by 50 |
R |
Reset to start |
Converting PDF papers
The reader takes plain text. To convert academic PDFs:
# macOS / Linux — install poppler-utils first (e.g. brew install poppler)
pdftotext input.pdf output.txt
Then drag the .txt file onto the reader page.
What it doesn't do (yet)
- A built-in file library — paste or drag, one paper at a time
- Per-paper bookmarks — single position memory
- Background sound / brown noise — planned for v1.2
- Browser extension packaging — planned for v2.0
- Multi-language ORP heuristics — currently tuned for English
Why RSVP works
RSVP (Rapid Serial Visual Presentation) shows words sequentially at a fixed location, eliminating the eye saccades that normal reading requires. For many readers — particularly dyslexic readers — this:
- Reduces visual-tracking effort
- Eliminates letter-reversal confusion (words don't sit next to each other)
- Enforces consistent pacing (no getting lost in a paragraph)
- Allows comfortable reading at speeds well above normal saccading limits
Brain comprehension is the real ceiling, not eye movement. RSVP lets you read closer to that ceiling.
Caveats
For academic citation work, use Sentence or Word mode in combination with the source PDF — RSVP is excellent for prose but cannot render tables, figures, or equations. The published recommended workflow:
- First pass via Sprint / RSVP at high WPM to get the paper's shape
- Second pass in the source PDF for the Methods, Results, tables and figures
- Capture exact quotes with page numbers from the PDF, not the RSVP stream
The abstract is an advert — don't cite it. Read the Introduction, Methods, Results, and Discussion. The meat is in the middle.
License
GPL v2 or later. See LICENSE.
Acknowledgements
Built as a study tool during an MSc thesis on accessibility-focused authentication research. Released as free software because reading subscriptions are a tax on poor researchers and accessibility tools should not be paywalled.