The history of RSVP: from 1970s labs to your iPhone
Showing text one word at a time in a fixed spot, RSVP (Rapid Serial Visual Presentation), was not born in a startup. It has spent more than half a century in reading psychology labs, and its history explains why it works and where its limits are.
1970 · Forster invents the tool
Psycholinguist Kenneth Forster was looking for a way to study how we process a sentence without letting the eye wander across the page. His solution was to present words one by one, in the same place, at high speed. He found something remarkable: the mind keeps understanding even when words arrive at a very high rate, around ten to sixteen words per second. Before it even had its name, RSVP had been born as a laboratory tool.
1984 · Potter gives it a name
Fourteen years later, Mary C. Potter, at MIT, formalized the method and gave it the name we know today in her work Rapid serial visual presentation (RSVP): a method for studying language processing. She showed that a sentence displayed word by word at about ten words per second can be understood and remembered. Her conclusion still holds: at moderate rates comprehension is maintained; when the pace is pushed, it drops. That is why an honest RSVP reader lets you choose the speed instead of promising miracles.
1992 · Rubin and Turano measure it
Gary Rubin and Kathleen Turano asked how much eye movement itself slows reading down. In Reading without saccadic eye movements they compared reading on a page with reading in RSVP: page reading was around 300 words per minute, while RSVP passed 1,100, with readers reaching 1,650 while keeping comprehension above 75%. From there came one of the technique's most valuable uses: low vision. If the eyes cannot move well across the page, let the text come to them.
2014 · Spritz and the boom
RSVP jumped from the lab to the pocket in March 2014. Boston company Spritz, after three years in secret, introduced a reader that highlighted each word's optimal recognition point in red and allowed reading between 250 and 1,000 words per minute. It arrived preinstalled on the Samsung Galaxy S5 and its Gear 2 watch. The headline about "reading a novel in 90 minutes" was exaggerated, but the wave showed that the format fits naturally on a small screen.
2016 · Science marks the limits
The boom's aftershock brought the most rigorous review to date: So Much to Read, So Little Time, signed by Keith Rayner, Elizabeth Schotter and, among others, Mary Potter herself. Their verdict is nuanced and honest: RSVP increases speed, but by showing a single word it takes away two things we use without noticing, the preview of what comes next and, above all, the ability to go back and reread when something does not fit. At extreme speeds, that hurts comprehension. The technique is real; the promise of reading everything three times faster without losing anything is not.
The real average reading speed: 238 words per minute
The figure of 300 words per minute that is often quoted in reading app marketing comes from studies conducted in the 1960s with small, unrepresentative samples. A 2019 meta-analysis by Marc Brysbaert of Ghent University took a different approach: it analysed 190 studies covering 18,573 participants and found that the actual average for silent reading is 238 WPM for non-fiction and 260 WPM for fiction. The gap matters. If your real baseline is 238 WPM, an app claiming to push you to "three times your normal speed" is promising 714 WPM — a figure the research consensus does not support for comprehension-intact reading. What the research does support is a realistic ceiling of 400 WPM for skilled readers on familiar prose without significant comprehension loss. Brysbaert (2019), Journal of Memory and Language.
Two things RSVP takes away: preview and the ability to go back
When you read normally, your eyes do something you do not notice: they look slightly ahead. The parafovea — the area just outside the focal point — pre-processes the next one or two words before they become the fixation target. This parafoveal preview gives your brain a head start on recognising the next word. RSVP, by definition, eliminates it: each word appears only when it must be read. The second cost is regression. Research by Rayner shows that skilled readers go back on around 10–15% of words — not because of bad habits, but because comprehension occasionally fails and the reader needs to repair it. RSVP makes regressions impossible without pausing the stream. These are not design flaws to fix — they are the fundamental tradeoff of the technique. Knowing them helps you use RSVP for what it is genuinely good at: familiar narrative text, articles, and content you do not need to study closely.
RSVP and low vision: a clinically validated use case
One of RSVP's strongest evidence-backed applications is not speed at all — it is accessibility. Rubin and Turano's 1992 work already pointed in this direction: if the eyes cannot move across a page, letting the text move to the eyes solves the problem. A 2001 study by Aquilante, Yager, Morris and Khmelnitsky published in Optometry and Vision Science added a practical refinement: low-vision patients with age-related macular degeneration read sentences 33% faster when the RSVP reader varied word display duration by word length — showing longer words slightly longer — compared to constant-duration presentation. Shorter words at a fixed pace create unnecessary cognitive friction; adapting the pace to word complexity reduces it. This is one of the details Leo applies: punctuation-aware pauses and a rhythm that follows the natural difficulty of the text, not just a fixed metronome.
Today · How Leo applies it
Leo takes what science supports and leaves out what it questions. It keeps the good part of RSVP (zero eye jumps, focus on one point, a pace you control) and answers its weak point directly: below the word sits the full chapter text, synchronized, so you can reread or jump anywhere with a tap. It adds natural pauses at punctuation and works with your own books in EPUB and PDF, with their images in view. The speed is always in your hands.
Want to try it with your books? Join the waitlist, the first people signed up will be the first to read with Leo.
References
This article is an accessible summary based on the following sources, which you can consult at the original links:
- Forster, K. I. (1970). Visual perception of rapidly presented word sequences of varying complexity. Perception & Psychophysics, 8, 215–221.
- Potter, M. C. (1984). Rapid serial visual presentation (RSVP): a method for studying language processing. In New Methods in Reading Comprehension Research (Erlbaum). View on Google Scholar.
- Rubin, G. S. and Turano, K. (1992). Reading without saccadic eye movements. Vision Research, 32(5), 895–902.
- Rayner, K., Schotter, E. R., Masson, M. E. J., Potter, M. C. and Treiman, R. (2016). So Much to Read, So Little Time: How Do We Read, and Can Speed Reading Help? Psychological Science in the Public Interest, 17(1), 4–34.
- Brysbaert, M. (2019). How many words do we read per minute? A review and meta-analysis of reading rate. Journal of Memory and Language, 109, 104047.
- Aquilante, K., Yager, D., Morris, R. A. and Khmelnitsky, F. (2001). Low-vision patients with age-related maculopathy read RSVP faster when word duration varies according to word length. Optometry and Vision Science, 78(5).