FAQ
Frequently asked questions
Quick answers about the tools, your data, and working with JSON. For longer walkthroughs, see the guides.
Privacy and security
Is my JSON uploaded to a server?
No. Every Json Works tool runs as JavaScript in your browser. The JSON, CSV, tokens and commands you paste are parsed on your device and never sent to us. Open your browser’s network tab while you use a tool to confirm that nothing is transmitted.
Is it safe to paste API responses with customer data?
Because nothing leaves your browser, the data is not exposed to us or to a third party by the tool. Your own organisation’s policies still apply, and you should avoid pasting live production secrets anywhere you do not need to.
Where is my history stored, and how do I delete it?
Recent inputs are saved in your browser’s IndexedDB for jsonworks.dev, on your device only. Use the Clear history button in a tool, or Clear all saved history in the footer, or clear your site data in the browser. We cannot see it and it does not sync between devices.
Do I need an account?
No. There is no sign-up, login or paywall.
Converting JSON to tables, CSV and Excel
How do I convert Postman JSON to CSV?
Copy the response body from Postman, paste it into the JSON to Table tool, check which array is used for rows, then click CSV. The step-by-step guide covers nested data and common problems.
What happens to nested objects and arrays?
Nested objects are flattened into dotted columns such as customer.address.city. Nested arrays stay compact as an expandable chip, and when you export you can keep them as JSON text, repeat the parent row for each item, or send each array to its own Excel sheet.
Why did Excel change my IDs or remove leading zeros?
When you open a CSV, Excel guesses each column’s type. It stores numbers as 64-bit floats, which are exact only to 15 digits, and drops leading zeros from values that look like numbers. Export to .xlsx, or import the CSV through Data > From Text/CSV and set those columns to Text.
Why do accented characters look broken in my CSV?
Excel only reads a UTF-8 CSV correctly if it starts with a byte order mark. Json Works adds one to its CSV exports. If a file from another source looks garbled, import it through Data > From Text/CSV and set the file origin to UTF-8.
What is the difference between the CSV and Excel exports?
CSV is plain text with no types or formatting. Excel (.xlsx) is a real workbook with a styled, frozen header row, filters and typed numbers, and it can hold several sheets.
How large a file can I convert?
Tens of megabytes and hundreds of thousands of rows work on a typical laptop, because only the visible rows are drawn. The practical limit is your browser’s memory. A worksheet itself holds at most 1,048,575 data rows.
JSON basics
Why does my JSON say it is invalid?
The usual causes are a trailing comma, single quotes, unquoted keys, comments, or text that was cut off when copied. The formatter reports the exact line and column. The guide on common JSON errors explains each one.
What is the difference between JSON and JSON Lines?
A JSON file holds one document, often a big array. JSON Lines (NDJSON) holds one complete JSON value per line, which suits logs and streaming. Json Works reads both.
Can JSON contain comments or dates?
Neither. JSON has no comment syntax and no date type; dates are normally ISO 8601 strings such as 2026-10-17T09:30:00Z.
When should I use JSON rather than CSV?
Use CSV for flat, tabular data that people open in spreadsheets. Use JSON when the data is nested, has optional fields, needs types, or is consumed by an API or program.
Other tools
Does JSON Diff care about key order?
No. Objects are compared by key, so {"a":1,"b":2} and {"b":2,"a":1} are equal. Arrays are compared by position, because their order is meaningful.
Which databases does JSON to SQL support?
PostgreSQL, MySQL, SQLite, SQL Server and Oracle. The generated types are a starting point; add primary keys, constraints and sensible lengths before using them in production.
Can the JWT decoder verify signatures?
Yes for HS256, HS384 and HS512 when you supply the secret, entirely in your browser. Decoding alone only shows what a token claims and does not prove it is genuine. Servers must always verify signatures.
Which cURL targets are supported?
fetch, Axios, Python requests, Node, PHP, or a structured JSON description of the request.
The site
Is Json Works free?
Yes. The tools are free and need no account. The site may show advertising to cover hosting and development; ads never see what you paste into the tools.
How do I report a bug or request a feature?
Email hello@jsonworks.dev. Include the tool name, your browser and what you expected. Please send a trimmed sample rather than real customer data.
Still stuck?
Read the common JSON errors guide or use the contact form.