Why Decoder exists.

The origin.

I built Decoder for someone I love.

She's autistic, and she reads people more carefully than anyone I know. Tone, subtext, the gap between what someone says and what they actually mean — she catches all of it.

But people keep telling her she's wrong. That she's overreacting, or reading into things. Usually nobody means any harm by it. It's just the default: her read gets treated as the anxious one, and the other person's gets treated as the plain truth.

The thing is, she's often right. The message did mean what she thought. The tone really was off. She picked up on something the other person didn't even know they were putting there.

So Decoder is built around one question: when you're not sure you're reading a message right, can something help you check — without just telling you what to think?

The promise.

Decoder does three things, and it tries to do all of them honestly.

• Decode.Paste a message you can't read. Decoder lays out the ways it might be meant, how likely each one is, and why. It won't pick one and hand it to you as the answer.
• Rehearse.Run through a conversation you're dreading before you have it. Decoder plays the other person the way they'd actually be — not nicer, not meaner. You get to practice.
• Notice patterns.The more you use it, the more it learns how the people in your life tend to communicate. When a new message looks like one you've seen before, it'll say so. What you do with that is up to you.

There are things it won't do, on purpose. It won't flatter you. It won't treat you like a problem to be fixed. And it won't pretend to know what someone meant when the message itself doesn't say.

Once in a while it'll push back — gently — if it looks like you're reading a message the way you tend to when you're tired or stressed. That's not a verdict. It's a nudge, and you're free to ignore it.

The line.

Decoder isn't a therapist. It isn't a coach, and it isn't a friend.

It's a tool — a careful one, I hope, but a tool. It can't help you grieve. It can't help you decide whether to leave someone. It can't tell you whether you're okay.

For any of that, you need a person. Sometimes that's a therapist, sometimes a friend, sometimes a stranger on a crisis line. The numbers are in the footer below.

What Decoder is for is the moment right before all that. The text you have to answer tonight. The email you've read ten times and still can't place. The conversation you want to practice before it's real. The small stuff that piles up when the world keeps insisting your read is the wrong one.

I built it because that pile used to land on one person. If it takes some of the weight off her — and off people like her — it's done its job.