About Read Books Fast
What it is
Read Books Fast is a free speed reading app. It shows a book one word at a time (or two or three at a time) in a fixed spot on the screen, so your eyes stay still while the text moves. This style of reading is called RSVP, short for rapid serial visual presentation.
It opens EPUB books, Markdown notes and plain text files. Everything runs in your browser.
Privacy
Your files are read entirely in this browser. Nothing is uploaded.
- The app has no server side. The site is a set of static files, and the reader has no code that sends data anywhere. Its content security policy also stops the page's code from sending data over the network (no fetch, XHR or WebSocket) and from loading anything from other sites.
- There is no account, no analytics and no cookies.
- Images inside a book are never loaded, and nothing in a book is ever run.
-
Your settings and reading positions are kept only in
this browser's
localStorage. Settings are the theme, word size, words shown at once, ramp-up and your last speed. For each of up to 50 recent books it keeps the title, your position, speed, words shown at once, word count and when it was saved. The text of a book is never stored. - To remove all of it, clear this site's data in your browser settings. A copy of the app opened from your own disk keeps its own separate storage.
Like any website, the hosting service delivers these page files to your browser and may keep ordinary request logs, such as your IP address and browser type. The books you open are never part of any request.
How it works
Focus letter. Each word is lined up on one letter, drawn in red between two small guide marks. This is the optimal recognition point, the spot where your eye takes in a word fastest. It is the first letter of a one-letter word, the second letter of a word with 2 to 5 letters, the third for 6 to 9, the fourth for 10 to 13, and the fifth for anything longer. Leading punctuation such as an opening quote is skipped.
Pauses. Punctuation gets a little extra time, so sentences keep their rhythm. Compared with a plain word, a comma or dash holds for 1.35 times as long, a colon or semicolon for 1.7 times, the end of a sentence for 2.2 times, the end of a paragraph for 2.6 times and the end of a chapter for 3.2 times. Long words get a little more: 1.15 times for more than 8 letters, 1.3 for more than 12 and 1.45 for more than 16.
Speed. You choose a speed between 100 and 1200 words per minute (WPM), in steps of 25. The default is 300. The pauses above are added on top, so the chapter and book time left that the app shows already includes them.
Chunks. You can show 1, 2 or 3 words at once. A chunk never runs past the end of a sentence or paragraph, and the focus letter sits on the middle word (the first of two).
Ramp-up. When Ramp up is on, which it is by default, each press of Play starts at 55% of your speed and reaches full speed over the first 4 seconds.
Pausing and resuming. While paused, the text around the current word appears below the reader, and you can click any word to jump to it. When you open a book you have read before, the app offers to resume where you left off.
Formats and limits
- EPUB books open if they are free of DRM. In a DRM-protected book the text itself is encrypted, and only the store's own reading app holds the key, so no other reader can turn it back into words. The app checks which files are encrypted: encrypted fonts are common and fine, but encrypted text means the book cannot be opened, and you will see a message saying so.
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Markdown files (
mdandmarkdown) and plain text files (txt) open as well. In Markdown,#and##headings start new chapters. A plain text file is one chapter. -
Images become a single marker word such as
[image]or[image: a short description], with a pause as long as a paragraph break. Math becomes[equation]. Chapters that hold only images, such as cover pages, are skipped. -
A code block becomes one
[code block]marker, because code depends on its layout and symbols and cannot be read one word at a time. Inline code keeps its text. - In a Markdown table each row is read as one paragraph. In an EPUB table each cell is read as its own short paragraph.
- Abbreviations such as "e.g." and "Mr." count as the end of a sentence, so they get a slightly longer pause.
- Very large EPUBs that need the ZIP64 format are not supported. Books are almost never that large.
- Only left-to-right text has been tested. Wide scripts such as Chinese, Japanese and Korean, and right-to-left scripts, will not line up exactly on the focus letter.
Keyboard shortcuts
| Space | Play / pause |
| ← → | Previous / next word |
| Shift+← → | Previous / next sentence |
| ↑ ↓ | Speed +25 / −25 WPM |
| [ ] | Previous / next chapter |
| R | Restart chapter |
| Esc | Pause and close panels |
| ? | Show the shortcut list |
Shortcuts are ignored while you are typing in a field, except Esc.
Browser support
Opening an EPUB needs a browser feature called
DecompressionStream with the
deflate-raw format. That means Chrome 80+,
Safari 16.4+ or Firefox 113+. Older browsers see a
message saying the browser is not supported.
A note on speed
Comprehension tends to drop at very high speeds, so slow down for material you need to remember. Pausing shows the surrounding text, which makes it easy to reread a sentence you missed.