API Mock Response Builder Guide
Describe fields once and generate realistic mock JSON for an API response.
A short companion for API Mock Response Builder: when it is useful, what it expects, and what to check before using the result.
What it does
Describe a response shape once as name: type pairs and the page generates a realistic JSON body with the number of records you ask for. It is the quick way to stub an endpoint, seed a fixture or show a frontend what the real payload will look like before the API exists.
Use the tool
Open API Mock Response Builder, add the input the tool asks for, run it, and check the output before using it elsewhere.
Input and output
- Input: text.
- Output: text.
- Category: Network.
Privacy and processing
Processing happens locally in your browser. This tool does not upload the input to ilham.dev.
Questions
What types can I use?
string, word, name, firstname, lastname, email, phone, city, country, address, company, product, url, image, uuid, id, number, integer, price, age, boolean, date, datetime, timestamp, color, object and array(n). Anything else is reported and skipped rather than guessed.
How do I get a list of values in one field?
Write array(3) for three items or array for a default of three. Each item is a short word, which is enough to fill a tags or categories field while you build the UI.
Are the values random every time?
Yes. Each render draws new values, and the Regenerate button does the same. If you need the exact same payload twice, paste the generated JSON into a file instead of regenerating.
Is the data based on anything real?
No. Names, addresses and emails are made up from small built-in word lists. They are deliberately fake so nothing generated can collide with a real person or mailbox.
Related guide
For broader background, see API Testing.