A
APIs Score

isEven (humor) API

Beginner's Pick Science & Math / No Auth Required Beginner HTTPS
Free to Use Varies (check documentation)
95 A+
Measured Score 0 50 100 Reachability 30/30 Speed 15/20 Security 15/15 Developer XP 20/20 Reliability 15/15 TESTED 2026-07-23
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Overview

isEven is a humorous free API that tells you whether a number is even or odd. It is intentionally over-engineered as a joke, turning a one-line math problem into an API call. It is a fantastic first API to practice HTTP requests because it requires no authentication and has the simplest possible input and output.

Beginner Tip

Just append any integer to the endpoint URL and you will get a JSON response immediately with no setup, no API key, and no authentication needed. This is the perfect API to test your first fetch() or curl command.

Available Data

joke text (setup/punchline)
joke category
joke type (single/twopart)
Use case: Integrate check if a number is even data into web and mobile applications

Example Response

JSON Response 
{
  "error": false,
  "category": "Programming",
  "type": "twopart",
  "setup": "Why do programmers prefer dark mode?",
  "delivery": "Because light attracts bugs.",
  "id": 42,
  "lang": "en"
}

Field Reference

iseven True if the number is even, false if it is odd.
ad A humorous advertisement shown on the free tier; safe to ignore.

Implementation Example

Request 
const url = "https://isevenapi.xyz/";
const response = await fetch(url);
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

400 Bad Request or error in response A non-integer value like a decimal or letter was passed in the URL.
✓ Only pass whole integers in the URL path, e.g., /api/iseven/7.
Unexpected ad field in response The free tier includes an ad field with a promotional message.
✓ Simply ignore or filter out the ad field in your code; only use the iseven boolean field.
CORS error in browser Browser security policy may block requests from certain origins.
✓ Make the call from a Node.js script or backend server to avoid CORS restrictions.

Measured Score Breakdown

Live HTTP request to the API endpoint

Reachability 30/30
Speed 15/20
Security 15/15
Developer XP 20/20
Reliability 15/15
Endpoint Response Time 445ms

Fully tested on Jul 23, 2026

How is this scored? →

Technical Specifications

Auth No Auth
HTTPS REQUIRED
CORS UNKNOWN
Category Science & Math
Difficulty Beginner
Verified: 2026-04-04

Related Tags

#science-and-math

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