Open Trivia

Overview

Open Trivia DB is a free, keyless trivia-question API with 4,000+ questions across 24 categories (General Knowledge, Books, Film, Music, Science, Computers, Sports, Geography, History…), three difficulty levels, and both multiple-choice and true/false formats. A favorite for quiz apps, game nights, and chatbot icebreakers.

Verified 2026-08: the API responds normally, but rate limiting is aggressive — a burst of requests returns HTTP 429. Space your calls out (a second or two between requests works).

Quick Start

Get one question:

curl "https://opentdb.com/api.php?amount=1"

Sample response (correct answer included — you decide what to do with it!):

{
  "response_code": 0,
  "results": [
    {
      "type": "multiple",
      "difficulty": "easy",
      "category": "Geography",
      "question": "Which Borough is the farthest in the north of New York City?",
      "correct_answer": "Bronx",
      "incorrect_answers": ["Queens", "Brooklyn", "Manhattan"]
    }
  ]
}

Filter by category / difficulty / type:

curl "https://opentdb.com/api.php?amount=10&category=18&difficulty=medium&type=multiple"

Avoid duplicates across sessions with a session token:

curl "https://opentdb.com/api_token.php?command=request"
curl "https://opentdb.com/api.php?amount=10&token=YOUR_TOKEN"

Categories (subset)

Authentication

None — keyless. (The session token is optional and only prevents question repeats.)

Rate Limits & Notes

• 429 responses are normal under bursts — throttle your client (a delay between requests).
• response_code: 0 = success, 1 = no results (e.g. empty token pool), 2 = invalid parameter, 3 = token not found, 4 = token empty (all questions used).
• Questions are community-contributed and occasionally contain typos or outdated facts.
• CORS is not guaranteed — call from a server or your own backend for reliability.

FAQ

Is Open Trivia DB free? Yes — free and keyless.

Why do I get HTTP 429? Rate limiting. Space requests out (a second or two apart) and it works fine.

How do I avoid repeated questions? Request a session token (api_token.php?command=request) and pass it with each call.