A
APIs Score

Numbers API

Science & Math / API Key Intermediate HTTPS
Varies by plan (check documentation)
74 B
Metadata Score 0 50 100 Metadata estimate · not endpoint-tested
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Overview

The Numbers API from math.tools provides facts, trivia, and mathematical data about numbers — including the number of the day, random numbers, and detailed number properties. An API key is required and you include it as a header in each request. It is a fun API for adding interesting number facts to educational apps, games, or daily fact features.

Beginner Tip

Include your API key as the "X-Api-Key" header rather than a query parameter for better security, and always check the "error" field in the response before trying to use the "result" field.

Available Data

randomly generated data
customizable output format
Numbers data via REST API

Example Response

JSON Response 
{
  "status": "success",
  "data": {
    "result": "Data from Numbers",
    "description": "Number of the day, random number, number facts and anything else you want to do with numbers",
    "timestamp": "2025-01-15T10:00:00Z"
  }
}

Field Reference

result Contains the main data about the number, including facts, properties, and classifications.
error True if the request encountered an error; false when the response is successful.
message A human-readable error description when the error field is true.
number The number you queried, echoed back in the response for confirmation.
fact An interesting fact or piece of trivia about the requested number.

Implementation Example

Request 
const url = "https://math.tools/api/numbers/";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
  headers: {
  "X-API-Key": "YOUR_API_KEY"
  }
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

401 Unauthorized The API key is missing, incorrect, or has expired.
✓ Sign up at https://math.tools to get your API key and include it in the X-Api-Key request header.
429 Too Many Requests You have exceeded your plan rate limit for the billing period.
✓ Check your usage dashboard on math.tools and consider upgrading your plan or adding request throttling to your code.
"error" field in response An invalid number or unsupported operation was requested.
✓ Ensure the number is within a valid range (try integers first) and check the API docs for supported number types.

Metadata Score Breakdown

Estimated from metadata — endpoint not independently tested

This score is estimated from observable metadata — HTTPS support, authentication model, declared CORS, and documentation reachability — because the API requires authentication or exposes no publicly testable endpoint. The five-signal breakdown is only shown for live-tested APIs.

Metadata estimate · endpoint not independently tested

How is this scored? →

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS NO
Category Science & Math
Difficulty Intermediate
Verified: 2026-04-04

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