Jot Format

Jot is a compact, human-readable JSON variant that uses fewer tokens for LLM applications.

JSON:

{"context":{"task":"Our favorite hikes together","location":"Boulder"},"friends":["ana","luis","sam"],"hikes":[{"id":1,"name":"Blue Lake Trail","km":7.5},{"id":2,"name":"Ridge Overlook","km":9.2}]}

Jot:

{context:{task:Our favorite hikes together,location:Boulder},friends:[ana,luis,sam],hikes:{{:id,name,km;1,Blue Lake Trail,7.5;2,Ridge Overlook,9.2}}}

Same data, 26% fewer tokens, still readable.

Why Jot?

• Save on LLM costs — Fewer tokens = lower API bills
• Fit more in context — Get more data into your prompts
• Human readable — Unlike binary formats, you can read and write it directly
• JSON compatible — Parses to the same JavaScript objects

Token Savings

Across 18 sample files, Jot averages 13% token savings.

| Sample | JSON | Jot | Savings | |--------|------|-----|---------| | users-50 | 1327 | 837 | 37% | | products | 772 | 613 | 21% | | large | 240 | 221 | 8% | | small | 37 | 36 | 3% | | irregular | 49 | 49 | 0% |

Full report →

Installation

npm / pnpm / yarn

npm i --save @creationix/jot

CommonJS

const { parse, stringify } = require("@creationix/jot");

ES Modules

import { parse, stringify } from "@creationix/jot";

Browser

Copy dist/jot.js to your project and import as a native ES module:

<script type="module">
  import { parse, stringify } from "./jot.js";
</script>

TypeScript

TypeScript definitions are included. You can also import src/jot.ts directly into your project.

Usage

import { parse, stringify } from "@creationix/jot";

// Parse Jot to JavaScript
const data = parse("{name:Alice,scores:[98,87,92]}");
// { name: "Alice", scores: [98, 87, 92] }

// Stringify JavaScript to Jot
const jot = stringify({ name: "Bob", active: true });
// {name:Bob,active:true}

// Pretty print with options
const pretty = stringify(data, { pretty: true, indent: "  " });

Syntax

Jot is JSON with three optimizations:

1. Unquoted strings — Strings are only quoted if necessary
2. Key folding — Single-key nested objects collapse: {a:{b:1}} → {a.b:1}
3. Tables — Arrays of objects with the same schema use {{:cols;row;row}} syntax

Here's a complete example showing all three:

{
  context: {
    task: Our favorite hikes together,
    location: Boulder,
    season: spring_2025
  },
  friends: [ ana, luis, sam ],
  hikes: {{
    :id, name, distanceKm, elevationGain, companion, wasSunny
      1, Blue Lake Trail, 7.5, 320, ana, true
      2, Ridge Overlook, 9.2, 540, luis, false
      3, Wildflower Loop, 5.1, 180, sam, true
  }}
}

Unquoted Strings

Quote a string only when:

• It's a reserved value (true, false, null) or a number (42, 3.14, -0.5, 1e10)
• It contains special characters: : ; , { } [ ] " or control characters
• It's empty or has leading/trailing whitespace
• It's a key containing . (to distinguish from folded keys)

{"name":"Alice","city":"New York","count":"42"}

{name:Alice,city:New York,count:"42"}

Key Folding

When a nested object has exactly one key, fold it:

{"server":{"host":"localhost"}}

{server.host:localhost}

If a key itself contains dots, quote it to avoid confusion:

{"data.point":{"x":10,"y":20}}

{"data.point":{x:10,y:20}}

Tables

Arrays of objects with repeating schemas become tables. Start with : followed by column names:

[{"id":1,"name":"Alice"},{"id":2,"name":"Bob"}]

{{:id,name;1,Alice;2,Bob}}

To change schema mid-table, add another :schema; row:

[{"id":1,"name":"Alice"},{"id":2,"name":"Bob"},{"x":10,"y":20},{"x":30,"y":40}]

{{:id,name;1,Alice;2,Bob;:x,y;10,20;30,40}}

Don't use tables when there's no schema reuse — regular arrays are more compact.