Comparison

How should a teleprompter trigger slides?

Three approaches exist: scroll-based deterministic triggering, voice-recognition auto-scroll, and manual operator control. Each has trade-offs. Here's the honest breakdown.

Trigger Methods

Three approaches. One question.

Which method reliably connects your script to your slides, lighting, and show cues?

Scroll-based (OtO)

Deterministic

Strengths

  • 100% reliable — triggers fire at exact script position
  • No microphone or audio processing required
  • Works in noisy environments (concerts, stadiums, live TV)
  • Operator retains full control — can pause, jump, override
  • Triggers any protocol: PowerPoint, QLab, MIDI, OSC, HTTP
  • Works offline, no cloud dependency

Limitations

  • Requires an operator to scroll the script

Voice-recognition (PromptSmart, etc.)

Probabilistic

Strengths

  • Hands-free scrolling — follows the speaker automatically
  • No operator needed for simple scroll use cases

Limitations

  • Voice recognition fails in noisy environments
  • Cannot trigger external cues (slides, MIDI, OSC)
  • Latency and drift — text lags behind speech
  • Requires clear audio input and consistent speech patterns
  • Unreliable for multi-speaker panels or live interviews
  • Cannot control PowerPoint or any downstream system

Manual triggering

Human-dependent

Strengths

  • No special software required
  • Full human judgment on timing

Limitations

  • Requires a dedicated operator per system
  • Prone to human error under pressure
  • No script synchronization — cues are eyeballed
  • Scaling to multiple outputs multiplies crew and cost
  • No automatic coordination between script and technical cues
Feature by feature

The honest comparison.

Capability
Legacy prompters
OtO
Network architecture
Centralized server , one failure kills the show
Peer-to-peer mesh with full state redundancy
Script as control surface
Passive text, no downstream effects
Action Markers fire MIDI, OSC, slides, macros
Hardware integration
Keyboard and mouse only
Loupedeck CT, Contour Shuttle, any MIDI surface
Multi-device output
Hardwired HDMI/SDI runs
Web, tablet, Android TV, mirror, beam-splitter
Newsroom protocol
Proprietary / expensive add-ons
Native MOS with bi-directional rundown sync
AI assistance
Cloud-only, vendor lock-in
Local-first, any OpenAI-compatible endpoint
Deployment cost
$20k–$80k per rig
Software license, runs on hardware you own

See scroll-based triggering in action.

OtO fires PowerPoint slides, QLab cues, MIDI commands, and OSC messages at exact script positions — no voice recognition, no manual clicking, no guesswork.

Try OtO free → Read the full comparison