M
API Matrix

Oxford API

Dictionaries / API Key Intermediate HTTPS
Varies by plan (check documentation)
69 Score
Grade C
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Overview

The Oxford Dictionaries API provides access to the Oxford English Dictionary's extensive lexical data, including definitions, pronunciations, etymologies, and usage examples. It requires an API key and application ID obtained by registering for a developer account, with a free tier for prototyping. This is one of the most comprehensive English dictionary APIs available, trusted by academics and developers worldwide.

💡

Beginner Tip

All requests require both an app_id and app_key passed as headers — unlike many APIs that use a single key. Start with the /entries endpoint to look up a word's definitions before exploring more advanced endpoints like /sentences or /translations.

Available Data

word definitions
pronunciation
synonyms and antonyms
example sentences
part of speech
Use case: Integrate dictionary 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

id The word_id (lowercase headword) used to identify this dictionary entry.
lexicalEntries List of lexical entries grouped by part of speech.
pronunciations IPA transcription and audio file URL for the headword.
senses Array of sense objects each containing definitions and example sentences.
etymologies Word origin and historical development information.

Implementation Example 

const url = "https://developer.oxforddictionaries.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

403 Forbidden One or both authentication headers (app_id, app_key) are missing or incorrect.
✓ Pass both app_id and app_key as separate request headers; they are available in your Oxford developer dashboard.
404 Not Found The word does not exist in the Oxford database or the language code is invalid.
✓ Use lowercase for the word_id and verify the language code (e.g., en-gb or en-us). Try the /lemmas endpoint to find the base form.
403 on free plan for advanced endpoints Some endpoints like /translations or /sentences require a paid subscription.
✓ Check the Oxford API pricing page to confirm which endpoints are available on the free prototype tier.

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 5/20
🔒 Security 15/15
🛠 Developer XP 9/20
✓ Reliability 10/15

Partially tested on Apr 5, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS NO
Category Dictionaries
Difficulty Intermediate
Verified: 2026-04-04

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