Browser-based teleprompter studio

Every screen on the same line. Every take on script.

Castrix turns any browser into a broadcast-grade teleprompter. Write your script, scan a QR code on any screen or phone, and go live — with perfectly synced displays, a phone remote, and three scroll modes including voice tracking. Bring a crew — or run the whole show yourself.

Try it free for 7 days — no card, nothing to cancel.
No installs Works on any screen 3 scroll modes No watermarks No word limits
Features

Built like a broadcast rig. Runs like a web page.

Everything a prompter operator expects — without the hardware cart, the cables, or the installs.

Screens that stay in sync

One controller drives every display — external monitors auto-fullscreen, iPads and iPhones pair with a QR scan. No apps, no installs.

Line-anchored sync

Every screen keeps the exact same line under its reading arrow — regardless of screen size or font size. No drift, no jumps, just a smooth glide.

Phone remote control

Scan a QR and your phone becomes the console: start/stop, speed, marker jumps, timers, even the emergency message. Bluetooth clickers work too.

Three scroll modes

Manual speed for classic operation. Timed mode to finish in exactly 4:00. Voice mode that follows your words — or scrolls only while you're talking.

Rich-text scripts

Bold, highlights, and colors — exactly what the host sees. Import .txt, .docx, or .pdf, get an instant read-time estimate, and save multiple shows.

Per-device flip & size

Mirror-flip any screen independently for beam-splitter rigs, and set text size per device. The talent's glass and the operator's monitor each get it right.

Clocks, timers & countdown

Time-of-day clock, count-up or count-down timer with a 0:00 flash, a 3/5/10-second countdown before scroll, and a progress bar with time remaining.

Works on any network

Direct peer-to-peer between your devices, with automatic HTTPS relay fallback when the venue's network fights back. It just connects.

Operator superpowers

You see everything. The host sees only the script.

Castrix keeps a private layer between the operator and the talent — so you can run the show without ever breaking it.

Operator-only notes

Annotate the script with cues, timing notes, and reminders that appear on your controller — and never on the host's screen.

Named markers & jump points

Drop invisible markers anywhere in the script. Jump between segments instantly from the controller or the phone remote — the host never sees them.

Emergency takeover

One tap launches a fullscreen, red-bordered private message to the host — "WRAP NOW", "GUEST CANCELED, PIVOT" — until you take it down.

Full remote command

Start, stop, adjust speed, jump markers, and run timers from a QR-paired phone anywhere in the room — or from a Bluetooth clicker in the talent's hand.

Solo creators

No operator? No problem.

Crewed shows get an operator console. Solo shoots get an invisible one — Castrix keeps pace with you, so you can be the talent, the operator, and the whole crew at once.

The script follows your words

Voice mode's "follow my words" speech tracking (in Chrome) listens as you read and keeps the script at your pace — speed up, slow down, pause for effect. Nobody at the controls, and it never runs away from you.

Scrolls only while you talk

Prefer any mic or mixer input? Scroll-while-talking moves when you speak and pauses the moment you stop — with a sensitivity control to tune it to your room. Flub a take? Just stop talking.

Finishes exactly on time

Timed mode takes a target — "finish in exactly 4:00" — and paces the whole script to hit it. No speed babysitting, no mid-take adjustments, no running long.

Start it from your hand

Hit record, get set during the 3/5/10-second countdown, and start, stop, or restart from the QR-paired phone remote or a Bluetooth clicker — without ever leaving your mark on camera.

One-person studio, broadcast-grade result.
How it works

From script to on-air in three steps

1

Write your script

Type it, paste it, or import a .txt, .docx, or .pdf. Style it with bold, highlights, and colors — and see the estimated read time instantly.

2

Scan a QR on any screen

Open Castrix on any monitor, iPad, or phone and scan the pairing code. Every screen snaps into perfect line-for-line sync. No installs, ever.

3

Go live

Hit start from the controller, your phone, or a clicker. Pick manual, timed, or voice mode — and let the glide engine keep every screen on the same line.

Pricing

Two plans. Pick the one that fits your rig.

Every scroll mode, every operator tool, and every import format is in both. Try it all free for 7 days — no feature gates during the trial.

Free trial

$0
7 days · full features
  • Every Castrix feature, unlocked
  • All three scroll modes
  • Phone remote & QR pairing
  • No credit card to start
Start free trial
Try it free for 7 days — no card, nothing to cancel.
Most popular

Individual

$8/mo
or $80/yr — 2 months free
  • The full teleprompter studio
  • Up to 2 external viewing screens
  • One phone remote
  • Unlimited shows & scripts
  • All three scroll modes
  • Operator notes, markers & takeover
  • Import .txt, .docx, .pdf
Choose Individual
Cancel anytime from your dashboard · Payments by Stripe

Pro

$25/mo
or $250/yr — 2 months free
  • Everything in Individual
  • Unlimited connected screens & devices
  • Unlimited phone remotes
  • Priority support — your email goes first
  • Cloud script library — opens on any machine you sign in on
  • Multi-user accounts — your team on one shared script library, a login each, no seat limit
  • Professional integrations — position, state and marker events out to playback and timing software
    Coming soon

The last item is not in Castrix yet. Pro subscribers get it at no extra cost on the day it ships. Everything above it works today.

Choose Pro
Cancel anytime from your dashboard · Payments by Stripe
A hardware prompter rig runs $500 to $5,000. Castrix replaces it for $8 a month — no cart, no cables, nothing to install.
Early access pricing — lock in these rates now; they're grandfathered when Castrix launches wide.
FAQ

Questions, answered

Do viewers need to install an app?

No. Every display — external monitor, iPad, iPhone — is just a browser tab. Scan the pairing QR code and the screen joins the show instantly. External monitors even go fullscreen automatically.

Does it work on iPad rigs with beam-splitter mirrors?

Yes. Mirror flip is set per device, so the iPad behind the glass can be flipped while your operator monitor stays normal. Text size is per-device too, so each screen is tuned for its distance.

What if the venue wifi is bad?

Castrix connects your devices directly, peer-to-peer, whenever possible — and automatically falls back to a secure HTTPS relay when the network blocks direct connections. It works over any network that can load a web page.

Can someone control the prompter remotely?

Yes. Any phone becomes a full remote by scanning a QR code — start/stop, speed, marker jumps, timers, and the emergency message. Bluetooth presentation clickers are supported as well.

How many screens and remotes can I connect?

Individual covers your operator machine plus up to 2 external viewing screens — enough for a talent iPad and a second monitor — and one phone as the remote. Your controller never counts against the allowance. Pro removes the ceiling on both, for multi-camera and multi-position rigs, or a remote in more than one pair of hands. Both plans save unlimited shows and scripts; Individual keeps them on the machine you write them on, Pro keeps them in your account so they open on any machine you sign in on and can be shared with your team. Compare the plans →

What formats can I import?

.txt, .docx, and .pdf. Scripts keep rich-text styling — bold, highlights, colors — and Castrix shows an estimated read time the moment your script loads. You can save multiple shows and switch between them.

What happens if voice tracking loses me?

It can, and the design assumes it will. Follow-my-words only moves the script on a contiguous run of matched words, so a cough or an ad-lib does not send it anywhere, and when it misses several results in a row it rescans the whole script for your place and demands a longer match before it moves again. If it still lands on the wrong line, you are never stuck: switch the scroll mode to manual speed or timed, scroll by hand, or jump to the nearest marker from the controller or the phone remote. Every screen is anchored to the line under the operator's arrow, so one correction on the controller is a correction on every display. We do not quote an accuracy figure. The promise is that recovery is always in your hands.

Why pay when free browser teleprompters exist?

A free prompter scrolls text in one tab. Castrix is the operator layer around it: a separate control surface, a QR-paired phone remote, and external screens that stay on the same line as the controller whatever their size or font. On top of that: timed mode that lands a script on an exact duration, operator-only notes and markers, the emergency takeover message, a cloud script library on Pro that opens on any machine you sign in on, and multi-user accounts on Pro. There are no watermarks and no word limits on any plan, and support goes to a person, not a form. If a single scrolling tab is all a shoot needs, a free tool is the right call. Castrix is for the shows where someone has to run it.

Your next take starts on the right line.

Set up your first show in minutes — script, screens, remote, live. Free for 7 days with every feature unlocked.

Start free trial
Try it free for 7 days — no card, nothing to cancel.