Free tool for product managers
Paste JSON from an API response, a webhook, a log or a ticket. The explainer shows its structure in plain language, flags dates, IDs, money, personal data and anything that looks like a secret — and nothing you paste leaves your browser.
Runs entirely in your browser — nothing is sent to TechPMer or anywhere else. Still, remove real customer data before pasting.
JSON (JavaScript Object Notation) is the text format most APIs use to send data. It has only a few building blocks:
| JSON | Looks like | Plain language |
|---|---|---|
| Object | { "name": "Ana", "plan": "pro" } |
A record with named fields — like one row in a spreadsheet |
| Array | [ 1, 2, 3 ] |
A list of items, in order |
| String | "Ana" |
Text — always in double quotes |
| Number | 42, 19.99 |
A number, without quotes |
| Boolean | true, false |
Yes / no |
| Null | null |
Deliberately empty — "no value" |
Objects and arrays can contain each other, which is how a single response can hold a user, their projects and each project's tasks.
"status": null for this order" is a far better ticket than "the page is broken".id, userId, order_id) connect records to each other — see databases for product managers.2026-09-25T09:30:00Z; the Z means UTC, so the UI has to convert to the user's time zone.1999 = $19.99) to avoid rounding errors — check which one your API uses.open, paid, refunded). Ask for the full list; every value needs a UI state.null and a field that is absent can mean different things. Agree which one the API uses.Paste a real (anonymised) example into your prompt: "This is the response from GET /api/orders/42. Show the status as a coloured badge; if refundedAt is not null, show 'Refunded on {date}'." Concrete examples remove guesswork. Remove real customer data and any secrets first.
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