About FlipLetters
FlipLetters is a web app that turns typed text and uploaded images into split-flap and flip-dot board videos, complete with synthesized mechanical click sound synced to every flip. It runs at app.flipletters.com, ships six board styles (station boards, flip-dot matrices, color-flap art boards, a desk marquee, and framed announcement boards), and is built by Terahertz Inc.
Why split-flap boards
Airport and train-station split-flap boards — and the flip-dot signs that share the same mechanical clack — have a specific, satisfying rhythm that’s hard to fake. Most tools that recreate the look skip the sound, or use a single looping click that doesn’t match how a real board actually moves: rows cascading, columns sweeping, a few stray characters spinning longer than the rest. FlipLetters builds the animation and the sound from the same underlying flip schedule, so a board sounds exactly as busy as it looks.
What you can make
Type a message across a few slides, choose how each one flips in (cascade, sweep, wave, dissolve, or a spinning random-lock “spin & settle”), and export an MP4 — landscape for YouTube, vertical for reels and TikTok, or square for feeds. Upload an image and FlipLetters quantizes it onto a color-flap or flip-dot grid as pixel art. Describe what you want in a sentence and Template Studio drafts a full design with Google’s Gemini model. Long-running ambience videos — the kind people leave on a TV like a fireplace loop — are a first-class use case, not an afterthought.
How it’s built
The animation engine is deterministic: the same project and seed always render the same video, frame for frame. That project format is also what powers the template marketplace — anyone can save a design, publish it to the public gallery, and reuse or sell it. The whole stack runs on Google Cloud / Firebase, and the click sounds are synthesized rather than sampled from any physical board, so every asset FlipLetters ships is one it actually owns.
Who’s behind it
FlipLetters is built and operated by Terahertz Inc., based in Virginia Beach, VA. Questions, feedback, or partnership ideas: support@flipletters.com.