M
API Matrix

Merriam-Webster API

⭐ Beginner's Pick Dictionaries / API Key Intermediate HTTPS
Varies by plan (check documentation)
72 Score
Grade B
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Overview

Merriam-Webster's Dictionary API provides authoritative English dictionary and thesaurus data from one of the most trusted publishers in the United States. It returns definitions, pronunciations, etymology, and example sentences in structured JSON. A free API key is available after registration, making it a solid choice for language learning apps and writing tools.

💡

Beginner Tip

Register at dictionaryapi.com and select the "Collegiate Dictionary" for general English definitions. Each API key is tied to a specific dictionary product, so make sure you use the key that matches the endpoint you are calling.

Available Data

word definitions
pronunciation
synonyms and antonyms
example sentences
part of speech
Use case: Integrate dictionary and thesaurus data data into web and mobile applications

Example Response

JSON Response 
{
  "word": "serendipity",
  "phonetic": "/ˌsɛr.ənˈdɪp.ɪ.ti/",
  "meanings": [
    {
      "partOfSpeech": "noun",
      "definition": "The occurrence of events by chance in a happy way"
    }
  ],
  "synonyms": [
    "luck",
    "fortune",
    "chance"
  ]
}

Field Reference

meta.id Unique identifier for the dictionary entry, typically the headword.
fl Functional label indicating the part of speech (e.g., noun, verb).
shortdef Array of short definition strings, ideal for quick display.
def Full definition array with sense divisions, verbal illustrations, and usage notes.
hwi.prs Pronunciation objects containing IPA transcription and audio file reference.
et Etymology information showing the origin and history of the word.

Implementation Example 

const url = "https://dictionaryapi.com/";
// 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

Response is an array of strings instead of entries The queried word was not found; the API returns spelling suggestions instead.
✓ Check the response type — if it is an array of strings, the word was not found; try the suggested spellings.
403 Forbidden The API key does not match the dictionary product endpoint being called.
✓ Make sure the key registered for "Collegiate Dictionary" is used with the /collegiate/ endpoint, not /thesaurus/ or others.
Missing audio file URL The audio base URL must be constructed manually from the response data.
✓ Build the audio URL using: https://media.merriam-webster.com/audio/prons/en/us/mp3/{subdir}/{filename}.mp3

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 5/20
🔒 Security 15/15
🛠 Developer XP 12/20
✓ Reliability 10/15

Partially tested on Apr 5, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS UNKNOWN
Category Dictionaries
Difficulty Intermediate
Verified: 2026-04-04

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