Best speed reading apps (RSVP) for iPhone
Note: Leo is our own app. We'll be straight with you, but keep that in mind.
The most studied speed reading technique is called RSVP (rapid serial visual presentation): text appears word by word at a fixed point, eliminating eye jumps. There are good apps that use it, and each one stands out in different ways. Here is an honest comparison, covering what each one does best.
What really matters in a speed reader
Almost all of them promise speed. What actually sets them apart is everything else: whether they read your own books (EPUB and PDF, not just pasted text), whether they let you keep track (go back, re-read, see images), whether the pace is yours (speed, pauses, typography), and which platform and language you live in. With that in mind, let's go through each one.
The apps, one by one
Spritz
Spritz is who popularized RSVP in 2014. Their technology, the optimal recognition point (that red letter that aligns each word in exactly the right spot), is one of the most recognizable in the industry. Today it mainly works as a licensed engine integrated into other apps and devices, rather than as a standalone reader. It shines at showing a perfectly positioned word in minimum space, even on a watch. It's not designed to open your EPUB or PDF with its own library, chapters, and images.
Spreeder
The veteran of web-based speed reading. Its strength is customization (various modes and lots of settings), a cloud library, and study tools like notes and color tags, with a gamified motivation angle (goals, rewards). It's geared toward productivity and training speed by pasting text or reading articles. As a full book reader on iPhone, with formatting and images, that's not its territory.
Reedy
A very capable RSVP reader, especially on Android. It boasts extreme speeds (up to 3,000 words per minute), adds a text-to-speech mode, and shows rich content (images, tables, notes) in its regular reader. Its limits: no PDF support and a slim iPhone presence.
Outread
The most direct rival within the Apple ecosystem: native on iPhone, iPad, and Mac. It does many things well: two methods (classic RSVP and guided highlighting), reading exercises, AI summaries and quizzes with Apple Intelligence, Pocket and Instapaper integration, and EPUB and PDF support. Very focused on articles and "read later". If you want the most complete toolkit on Apple, it's a great option.
Leo
Leo does one thing and does it well: reading your entire books, EPUB and PDF, with RSVP without missing anything along the way. Below the word you get the full chapter text, synced and clickable, so you can re-read or jump wherever you want (exactly what science points to as RSVP's weak spot). If your EPUB has illustrations, you see them in context while you read. Adjustable speed with natural pauses at punctuation, light, sepia, and night themes, fonts and sizes. And the interface, out of the box, in English, Spanish, and French.
Comparison table
| Platform | Your books | Full text alongside RSVP | Spanish interface | |
|---|---|---|---|---|
| Leo | iPhone | EPUB and PDF | Yes | Yes |
| Spritz | Engine / SDK | No (it's technology) | No | No |
| Spreeder | Web and app | Pasted text / web | No | No |
| Reedy | Android | EPUB (no PDF) | No | No |
| Outread | iPhone, iPad, Mac | EPUB and PDF | No | No |
What about comprehension? What almost no one tells you
No app will make you read at 1,000 words per minute and understand everything. The most rigorous scientific review on the topic (Rayner, Schotter, and RSVP pioneer Mary Potter herself, in 2016) makes it clear: RSVP increases speed, but showing one word at a time removes the possibility of going back to re-read, and that takes a toll if you push the pace. That's why in Leo speed is a dial, not a promise, and you have the full text handy to re-read when something doesn't click. We cover this in detail in the history of RSVP.
So, which one should I choose?
If you want the most famous and minimalist engine, Spritz. If you live on the web and like settings and coaching, Spreeder. If you're on Android and looking for extreme speed or text-to-speech, Reedy. If you want a complete Apple toolkit with AI and "read later", Outread. And if what you want is to read your own books faster without losing the thread, on iPhone, that's where Leo comes in.
Leo is coming soon to the App Store. Join the waitlist and be among the first to try it.