Overview
Some letters arrive with a government seal, a deadline, and no plain explanation of what they mean or what you are allowed to do about it. Decoder reads that letter back to you in plain language: what it is, the deadline buried inside it, the rule it cites, and your rights. It never tells you what to do.
It runs entirely in your browser. The text you paste, including anything carrying your Social Security number, never leaves your device, and it works offline. Five decoders are live: IRS notices, VA letters, special-education (IEP) paperwork, eviction notices, and immigration notices.
The line that makes it safe
There is a bright legal line between explaining a notice and giving advice. “What does this letter mean, and what are my rights” is public information. “What do I owe” or “what should I claim” is regulated advice, and getting it wrong can hurt someone.
So the whole tool is built on one rule: describe the rule, never apply it to your facts. It reads the dates and amounts the agency already printed on your letter and does the calendar math, but it never computes your number or tells you what to choose. That single constraint is what lets a tool like this exist responsibly.
A fixed shape for every notice
- What it is: The notice named in plain words, with the fear-driving jargon translated.
- Your deadline: The date read off your own letter, days remaining counted, overdue states flagged.
- The rule it cites: A link to the actual statute or regulation, so you can read the source, not my paraphrase of it.
- Your rights and next steps: What you are entitled to do, described without prescribing which option to take.
- Free expert help: Every decoder ends by pointing to free, accredited help: tax clinics, veterans’ service officers, parent centers, legal aid.
Designing for trust, not engagement
People reading these letters are often frightened, so the design works to lower the temperature rather than raise it. Out went anything that reads like a content farm: emojis, exclamation, decorative bullet lists. In came quiet line icons, a calm type scale, and urgency shown as a restrained color state rather than an alarm.
Trust also meant being honest about the tool’s own limits. Every decoder carries a “last reviewed” date and a plain note: if something looks different from your paper letter, trust the letter. Urgency badges were tuned to pass WCAG AA contrast in both themes, and the immigration decoder carries an explicit warning that only licensed attorneys or accredited representatives may give advice.
One engine, many bodies of law
Under the surface it is a single deterministic engine fed a separate knowledge base per domain, so a new decoder is a small authored file rather than a new app. That is how it grew from one IRS tool into five areas of law in days.
The hard part was never the code; it was accuracy. Legal facts were checked against primary sources rather than trusted to a single model pass, after an early test where asking one model the same question three times returned three different answers. That discipline is how a real error got caught: a veterans’ appeal deadline had been written as unextendable when the Supreme Court has held that it is not.