The line reader app
that reads every other part
Offbook is an AI script reader for actors. Upload your sides or the full script and pick your role. AI voices read the rest of the cast, and Offbook listens while you speak, then plays the next cue when you finish your line.
What is a line reader app?
In an audition, the reader is the person who says every line that is not yours, so casting can watch you instead of the page. In rehearsal, it is whoever you can talk into holding the script. A line reader app does that job when nobody is free. For more on the human version, see what a reader does in an audition.
Line reader apps differ in two ways, and together they decide how useful an app is: where the other voices come from, and how the app knows when to play the next cue.
- The voices. Some apps play recordings that you or a friend make of every other line. Recording costs nothing, but it takes time to set up, and you record again after every rewrite. Others read the lines with a computer voice, or with AI voices that read straight from your script, so there is nothing to record.
- The timing. Some apps leave a fixed gap after each cue, which rarely matches your pace, or wait for you to tap, so you rehearse with one hand on the screen. Others listen: they hear you finish your line, or its last word, and then play the next cue. Listening is the closest an app gets to a person reading with you.
Offbook uses AI voices and listens for the end of your line. You bring the script you already have, and the reader is ready a few minutes later.
Used by actors from top institutions
Training at the world's leading drama schools and theaters
How an AI script reader for actors works
From a PDF to your first full run in four steps
Upload the script
Add a PDF, a PNG or JPEG of the pages, or a text file. Offbook sorts the pages into characters and lines and writes a short summary of the scene.
Pick your role
Choose the character you play. Every other character gets an AI voice, and you can change any voice before you start.
Hear your cues
The reader plays the line before yours and listens through your microphone. When you finish your line, the next cue plays.
Take the script away
Hide your lines, switch to first-letter cues, then hide the whole script. The reader keeps going either way.
How the reader knows you finished your line
Timing is the whole point of a reader. A cue that comes too early cuts off your thought; one that comes too late teaches you to wait. Offbook listens through your microphone while you speak and compares what it hears with your line in the script. When it detects the end of your line, it plays the next cue.
You choose how closely it listens:
- Strict stays close to the script. Use it when you are nearly word perfect and want the slips to show.
- Lenient has a leniency slider from 0 to 100. Use it while the words are still coming, so a small paraphrase does not stop the scene.
- Manual never moves on by itself. The next cue plays when you press Enter or say “next line”.
You can also turn on auto-advance, so the scene moves on after 1 to 6 seconds of silence. And whatever the mode, you can always press Enter or say “next line” if you go up and want to keep the scene moving.
Two habits make the listening work better. Wear headphones, so the reader's voice stays out of your microphone. And give very short lines, like “Yes.” or “Oh?”, a clear finish, because one-word lines are the hardest to detect.
How to memorize lines with a line reader app
A reader on its own does not get you off book. What gets you off book is pulling each line out of memory when you hear its cue, again and again, with less help each time. Here is a plan that uses the reader for exactly that.
- Hear the whole scene first. Listen mode plays the entire scene aloud, your lines included, once its audio is generated. Play it on your phone on the way to work, with your own lines spoken, skipped, or left as silent gaps.
- Run it with the script in view. Say your lines out loud on cue. Slow the reader down with the playback speed setting if the cues come too fast to think.
- Switch to first-letter cues. Your lines turn into the first 1 to 8 letters of each word. Start with three letters, drop to one, then show only the first word of each line.
- Hide your lines. Everyone else's lines stay visible, so you can still follow the scene, but yours are gone. This is where the real learning happens.
- Loop the scene. Scene looping restarts the scene when it ends, so you can run it five times without touching the keyboard.
- Hide the entire script. When you can run the scene clean with nothing on screen, you are off book. Switch line detection to Strict for one last check.
Want to try the first-letter step on paper first? Our free line memorizer turns any text into first-letter cues in your browser. For the memory research behind this plan, read how to memorize lines quickly.
Using a line reader app for self-tapes
Most self-tape trouble starts before the camera rolls: you know the lines on paper but not in the rhythm of the scene. Run the sides with the reader until the cues feel like someone talking to you, not a list you are waiting through.
Then shape the read to suit the scene. Change the playback speed of a single line so a fast exchange stays fast. Add a pause before a cue where your character needs a beat. If a character sounds wrong for the scene, give them a different voice. If the sides have a typo or a line on the wrong character, fix it in the scene editor.
For the take itself, read the casting instructions first. Some ask for a live reader, and you should follow them. If an app reader is fine, record on your phone or camera as you normally would, put the laptop running Offbook right beside the lens, at the side you play to, and turn it down so it is quieter than you. The reader sits closer to the microphone than you do, so a level that sounds right in the room usually sounds too loud on the tape.
For the full setup, from eyeline to sound, see how to self-tape without a reader, and for what casting thinks of AI voices, read can an AI voice be your self-tape reader.
Line reader app vs. a human reader
An app covers the hours of repetition, at any hour, with nobody to book. A person is there when you schedule them.
- When it is available
- Line reader app: Any hour, as often as you like
- Human reader: When they are free and nearby, or on a call
- Repetition
- Line reader app: Runs the same two pages forty times in a row
- Human reader: Patience runs out, and favors pile up
- Waiting for your line
- Line reader app: Listens for the end of your line, or waits for Enter
- Human reader: Yes, naturally
- How you shape the read
- Line reader app: Set the speed of any line or add pauses before cues
- Human reader: Explain what you want and hope the next take lands
- Help with the scene
- Line reader app: Ask Genie about motivation, the scene, or how to read a line
- Human reader: Yes, if they are an actor or a coach
| Compared on | Line reader app | Human reader |
|---|---|---|
| When it is available | Any hour, as often as you like | When they are free and nearby, or on a call |
| Repetition | Runs the same two pages forty times in a row | Patience runs out, and favors pile up |
| Waiting for your line | Listens for the end of your line, or waits for Enter | Yes, naturally |
| How you shape the read | Set the speed of any line or add pauses before cues | Explain what you want and hope the next take lands |
| Help with the scene | Ask Genie about motivation, the scene, or how to read a line | Yes, if they are an actor or a coach |
Learn the words, the cues, and the timing with Offbook, and run the scene as often as it takes. If casting asks for a live reader, you arrive with the lines already learned, so the session goes to the acting. When you want a partner for the whole scene rather than a reader for your sides, see our AI scene partner.
What to look for in a line reader app
- It reads your script, not a script you retype. Sides arrive as PDFs and screenshots. Offbook takes PDF, PNG, JPEG, and TXT files, and a phone can upload camera photos or pasted text.
- It handles a full play. One Offbook scene holds up to 50 pages or about 10,000 words, and the page picker splits up to 150 source pages into 10 scenes.
- It waits for you. A reader that listens lets you take your time on a hard line and pick up the pace on an easy one.
- Every character sounds different. When each role has its own voice, the cue itself tells you who is speaking. Free and Starter cast from 12 voices; Pro and Premium cast from a larger catalog.
- You can shape the read. Speed, pauses, and voice choice turn a flat read into a usable cue.
- It takes the text away. Hidden lines, first-letter cues, and a hidden script move you from reading to remembering.
To see how different apps score on these points, read our guide to the best line learning apps.
Try a free line reader first
If you want to see how running lines with a reader feels before you sign up, use our free run lines online tool. Pick a classic scene and your part, and Offbook’s voices read the other characters, then stop on each of your lines. It needs no account.
Offbook is the full version of that idea. You upload the script instead of pasting it, AI voices give each character a voice of its own, and the reader listens for the end of your line instead of waiting for you to press a key. It also has hidden lines, first-letter cues, a teleprompter that highlights each word as you say it, and Genie, a script assistant you can ask about motivation, subtext, and what a line means.
Beyond expectations
Offbook is transforming how actors prepare for their roles, enabling faster memorization and deeper character work across theater and film.
“This saved my finals. I was running lines on this app at 2AM so I could practice my three scenes as many times as I needed.”
Drama Student • Fordham University
“My new line-learning process is simple, get my sides, pop them into Offbook, drill. No more bugging my friends to read for me.”
Film & TV Actor • Los Angeles
“You can clearly see in the quality of the application that it was built by actors who know what they're doing. Very detailed and useful. I really like it.”
Stage Performer • New York City
“I like that Offbook never gets frustrated when I need to repeat sections over and over. I can actually focus on my delivery.”
Film & TV Actor • Chicago
“Started using this for my conservatory work. I really like the chat feature where I can validate my script analysis and get a second opinion.”
Theater Graduate • DePaul University
“Got sides last minute while I was traveling. I didn't have anyone to run with, so I rehearsed on the app in my hotel room. By the end, I felt ready to tape.”
Actor in-training • HB Studios
Line reader app FAQ
What is the best line reader app for actors?
Pick one that starts from the script you already have, waits for you to finish your line instead of playing on a timer, and takes your lines away in stages. Offbook does all three: upload a PDF or a photo of your pages, choose your role, and AI voices read every other character while Offbook listens for your line. For a wider comparison, read our guide to the best line learning apps.
Is there a free line reader app?
Our free run lines online tool lets you rehearse classic scenes: Offbook's voices read the other parts and stop on each of your lines. It needs no account. Offbook itself starts with a 7-day free trial on every plan, and a card is required. Free Offbook accounts can also practice scenes that a castmate on a paid plan shares with them.
Does an AI script reader react to how I say my line?
No. Offbook listens to know when you have finished your line, then plays the next cue. It does not change its read because of your choice. You shape the read yourself with the voice you pick, the playback speed of each line, and pauses before a cue.
Can I use a line reader app for a self-tape?
For rehearsing the tape, yes. For the take, check the casting instructions first, because some ask for a live reader. If an app reader is fine, record on your phone or camera as usual, put the laptop running Offbook beside the lens, and keep its volume below yours.
Do I have to say every line word for word?
Only if you want to. Choose Strict to stay close to the script, Lenient with a 0 to 100 leniency slider while you are still learning, or Manual, where the reader moves on only when you press Enter or say "next line". You can also have it move on after 1 to 6 seconds of silence.
What scripts can the line reader read?
PDF, PNG, JPEG, and TXT files. One scene can hold up to 50 pages or about 10,000 words, and the page picker can split up to 150 source pages into 10 scenes, so a full-length play fits. You can edit any line the upload got wrong and move a line to a different character.
Can I use the line reader on my phone?
Rehearse on your laptop with the full script on a big screen, and listen to your scenes on your phone anywhere. Rehearsing out loud with cues works in a laptop or desktop browser, Mac or Windows. On a phone, your own lines can be spoken, skipped, or left as silent gaps, and playback keeps going with the screen locked. An iPhone app is coming soon.
How much does Offbook cost?
Every plan starts with a 7-day free trial, and a card is required. After the trial, Starter is $9.99/mo, Pro is $14.99/mo, and Premium is $29.99/mo. Annual billing starts at $7.99/mo. Students and educators get 50% off with a valid .edu email.
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