Building a Synesthesia Visualizer for Valentine's Day

My girlfriend has synesthesia — she sees colors when she reads or hears words. Every letter has a specific color in her mind, and words become gradients that blend those colors together. When she first told me about it a few years ago, I did what any reasonable person would do: I tested her.

I showed her the alphabet at random intervals across several days, asking her to assign a color to each letter. She was remarkably consistent, so I logged the results and created a color key — a complete map of her letter-to-color associations. I took a photo of it and held onto it, figuring it would be useful someday.

The App

This Valentine’s Day, I built Synesthesia Visualizer so I could finally see what she sees. You type a word or phrase, and the app renders the color gradient that her brain generates — each letter contributing its mapped color to a smooth blend across the text.

The core of it is simple: look up each character’s color from the profile, then render a gradient.

Features

Beyond the basic visualizer, I added a few things to make it more useful:

• Gradient rendering — words display as smooth color blends based on each letter’s assigned color
• Shareable links — generate a share dialogue so you can send someone a word rendered in your color profile
• Import/export color profiles — synesthesia is unique to each person, so anyone can create and load their own letter-to-color mappings

That last feature is the one I’m most glad I included. Synesthesia varies wildly between people — my girlfriend’s “A” might be red while someone else’s is green. The import/export system means anyone with grapheme-color synesthesia can map their own alphabet and use the tool.

Try It

The app is live at synesthesia.sch.xyz. If you or someone you know has synesthesia, load up a custom color profile and see how your words look.