Calculator
What the JSON to TypeScript does
JSON to TypeScript: converts Status and TypeScript from JSON, Root interface name and Mark properties optional. Example: root interface name Root and mark properties optional No (all required) gives status 3 interface(s) generated.
Status and TypeScript, derived from JSON, Root interface name and Mark properties optional. Edit a field and the answer updates in place.
Typical users are developers debugging a payload. Spotting a malformed field is far quicker when the structure is laid out clearly.
Payloads stay in the tab, so you can safely paste production data without it reaching a third party.
If you want to check the arithmetic, the field table, the method and a worked example are further down.
What do the JSON to TypeScript fields mean?
The JSON to TypeScript uses 3 inputs. You can work from the defaults, or clear them and start fresh, both work.
| Field | What to enter | Default |
|---|---|---|
| JSON | paste or type any amount of text | { "id": 42, "name": "Ada", "email": "ada@example.com", "active": true, "tags": ["admin", "dev"], "address": { "city": "London", "zip": "N1" }, "orders": [{ "id": 1, "total": 19.99 }, { "id": 2, "total": 5 }] } |
| Root interface name | required | Root |
| Mark properties optional | choose from No (all required) or Yes (all optional) | No (all required) |
How does the JSON to TypeScript work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same conversion.
Nothing is computed until the inputs pass their checks, so you will not get a confident answer built on a typo.
Worked example
These are the values the JSON to TypeScript loads by default, and the result it produces from them. Here is the calculation as it stands the moment the page loads.
| JSON | { "id": 42, "name": "Ada", "email": "ada@example.co… |
|---|---|
| Root interface name | Root |
| Mark properties optional | No (all required) |
| Status | 3 interface(s) generated |
|---|---|
| TypeScript | export interface Root { id: number; name: string; email: string; active: boolean; tags: string[]… |
Read next: JSON Formatting: The Rules People Get Wrong
How to use it
- Paste your content into JSON.
- Type Root interface name.
- Pick a value for Mark properties optional: the options are No (all required) or Yes (all optional).
- Type a value and the answer is already there by the time you stop.
- The panel reports Status and TypeScript.
- Copy Link is the quickest way to send the exact scenario to someone else.
What this tool does not do
- Output follows the common convention for this format; a specific toolchain may have its own house style.
- Processing happens in your browser, so very large inputs are bounded by available memory.
- Results are informational: check anything consequential against a second source.
Frequently asked questions
Just JSON, Root interface name and Mark properties optional. Nothing starts empty, meaning you can explore the calculation before committing to real figures.
With the values loaded when the page opens, status comes out as 3 interface(s) generated. Any edit re-runs the calculation, so there is no stale number on screen.
Nothing is logged. The tool is client-side code; your data stays where you entered it.
Nothing at all. There is no registration, no paywall and no per-use quota.
The output is deterministic. The same inputs always give the same answer, and the method is documented above so you can check it.