OpenCaption Live Brandon Lopez

Captions that don't need the venue's wifi.

A Mac in your rack becomes a dedicated captioning box: mic feed in, styled caption window out. Word-by-word, entirely offline — pull the venue's internet after setup and captions keep running.

Ask about early access

Built for the show.

Not the demo. The show, mid-keynote, when it counts.

01Fully offline

No cloud. No per-minute billing.

Speech recognition runs on-device using Apple's speech engine. There is no cloud transcription service in the pipeline and no captioning traffic on your network — the only calls the app ever makes are a one-time OS model download and a license check.

After that, the venue's internet is irrelevant to your show.

02Word by word

Tracks speech instead of trailing it.

The engine streams partial words as they're spoken — real word-by-word delivery, not caption blocks landing a full clause behind the speaker.

Output is a normal macOS window, so it drops straight into the video path you already run: window capture in your switcher, a second output to a confidence monitor or IMAG screen, keyed into a stream layout.

03Made to match

Your client's look, not a template.

  • Font, size, weight, spacing, alignment — auto-scaling with the window
  • Colors, opacity, box width, anchored positioning for lower-thirds
  • Per-character fade-in, configurable visible lines
  • Named, saveable presets recalled instantly next show

All of it live in a preview pane while you adjust.

04Mid-show proof

The failure modes, handled up front.

  • Display never sleeps mid-session — quiet rooms included
  • Mic disconnects detected immediately, remembered by hardware identity
  • Stranded caption windows find their way back to a live display
  • Tunable pause behavior — fast panels and deliberate keynotes both work
  • One-click, content-free diagnostics safe to hand to anyone

Nothing is recorded.

The part that closes the deal.

Audio and captions exist in memory for the duration of a session and nowhere else. Nothing written to disk, no transcript log, no analytics, no tracking. For corporate, legal, government, and religious events — anywhere what's said on stage isn't meant to leave the room — that isn't a footnote. It's the requirement.

Requirements.

If your rig already matches this, you can run it day one.

A Mac with Apple Silicon (M1 or later) and 16GB+ RAM, running macOS 15 or later.

A mic feed — board feed, wireless receiver, USB mic, anything the Mac can see.

No specialized hardware, no capture card, no dedicated captioning workstation, no remote captioner on standby.