Word Ladder Generator API

GET

Create solvable word ladder puzzles with custom difficulty levels.

Word Ladder Generator creates puzzles where players transform one word into another by changing one letter at a time, with each step forming a valid word.

Try it — live request, no key required

Request

GETapi.apiverve.com/v1/wordladder

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "puzzles": [
      {
        "startWord": "ANIL",
        "endWord": "CUED",
        "steps": 5,
        "solution": [
          "ANIL",
          "ARIL",
          "ARID",
          "IRID",
          "IRED",
          "CRED",
          "CUED"
        ],
        "solvable": true,
        "difficulty": "medium"
      }
    ],
    "count": 1,
    "difficulty": "medium",
    "html": "<html><head><title>Word Ladder</title><style>body {font-family: Arial, sans-serif; padding: 20px; max-width: 600px; margin: 0 auto;}h1 {text-align: center; color: #4CAF50;}.puzzle {background: #f5f5f5; padding: 25px; margin: 20px 0; border-radius: 10px;}.words {display: flex; justify-content: space-between; align-items: center; margin: 20px 0;}.word {font-size: 28px; font-weight: bold; letter-spacing: 3px; padding: 15px 25px; border-radius: 10px;}.start {background: #4CAF50; color: white;}.end {background: #2196F3; color: white;}.arrow {font-size: 30px; color: #999;}.steps {text-align: center; font-size: 14px; color: #666; margin-bottom: 15px;}.ladder {display: flex; flex-direction: column; align-items: center; gap: 10px; margin: 20px 0;}.rung {width: 150px; height: 40px; border: 2px dashed #ccc; border-radius: 5px; display: flex; align-items: center; justify-content: center; font-size: 18px; letter-spacing: 5px;}.hint {font-size: 13px; color: #888; font-style: italic; margin-top: 10px;}</style></head><body><h1>Word Ladder</h1><p style='text-align:center;'>Change one letter at a time to get from the first word to the last</p><div class='puzzle'><div class='steps'>Puzzle #1 - 5 steps</div><div class='words'><span class='word start'>ANIL</span><span class='arrow'>→</span><span class='word end'>CUED</span></div><div class='ladder'><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div></div></div></body></html>",
    "image": {
      "imageName": "6f0f9e5e-ce0d-4570-a706-8fc5ccbfc948_wordladder.png",
      "format": ".png",
      "downloadURL": "https://storage.googleapis.com/apiverve/APIData/wordladder/6f0f9e5e-ce0d-4570-a706-8fc5ccbfc948_wordladder.png?GoogleAccessId=635500398038-compute%40developer.gserviceaccount.com&Expires=1766010731&Signature=FQwH%2FqXC0eYHgHqGKfBoEETrcXALoIpkf2z7HCkmYcFu2IgL2uMbCBi22tEsrlY3yOkksRuZ56C2685lLi98CWvgCF1J9UrYaAWjFtLesnHZ0i%2B0SWYIy5wZLWnVq4UrJDLZVrvSe8lh21mQJrduVY8QqV%2FI0sViUlnlndLMFUfhEQedKYAGRtmXjJlpl1YA9A9%2BtJoqRvMm4YStfJyLJmExPQKnPiRoP6EB6%2B8%2F1WUq5vH3%2BWglijVroxaJ%2BJy6kgQ8qTuVX9%2FzFi8R0DDHZtd0IpcTL8EBvNvHnjRPS4lZB%2Bm3k9GCxqGCnsj8pssu6ymtzGNEqA%2BBqAthODekWw%3D%3D",
      "expires": 1766010731681
    }
  }
}

About the Word Ladder Generator API

Returns the puzzle, solution path, and step count. Includes printable HTML with empty rungs for solving.

What people use it for

Word Games: Create word ladder challenges for puzzle apps
Education: Teach vocabulary and word relationships
Brain Training: Develop problem-solving and word skills
Competitions: Generate puzzles for word game tournaments

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON: Default REST response
XML: Markup format
YAML: Human-readable
CSV: Tabular export
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use Word Ladder Generator

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit

Questions.

Common questions about the Word Ladder Generator API.

Read the docs →

What word lengths and difficulty settings are supported?

You can supply starting and ending words between 3 and 6 letters in length, provided both words have identical character counts. The generator also lets you request specific difficulty levels like easy, medium, and hard, and generate multiple puzzles in a single request.

Is it cheap enough to give every player a fresh word ladder?

Yes. Each generation call consumes 2 credits, giving you 100 free calls each month. On the Starter plan, 1,000 calls cost about $0.30, working out to $0.0003 per puzzle request across 100,000 monthly calls.

Do I get the solution path and printable templates on the Free plan?

No. The step-by-step solution path, printable HTML layout with empty rungs, and downloadable puzzle images are premium features. Any paid plan unlocks access to full solutions and visual puzzle assets.

What happens if a word pair cannot be solved?

Every generated puzzle object contains a solvable boolean field. If no valid sequence of single-letter substitutions connects the start and target words, this flag reports whether a solution path exists so your app can handle unsolvable pairings gracefully.

Can Word Ladder Generator create visual puzzles ready for printing?

Yes, on paid plans. The endpoint can generate printable HTML templates structured with blank ladder rungs for manual solving. When enabled on a paid plan, it can also return an image download URL pointing directly to a rendered puzzle graphic.

Request parameters — GET /v1/wordladder

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Optional

Parameter	Type	Example	Description
`start`Optional	string	`cold`	Starting word (3-6 letters) length 3-6
`end`Optional	string	`warm`	Ending word (same length as start) length 3-6
`difficulty`Optional	string	`medium`	Difficulty level `easymediumhard` default medium
`count`Optional	integer	`1`	Number of puzzles default 1 · range 1-5
`image`OptionalPremium	boolean	`true`	Set to true to generate a downloadable puzzle image default false

Example request

1
2

curl "https://api.apiverve.com/v1/wordladder?start=cold&end=warm&difficulty=medium&count=1&image=true" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — GET /v1/wordladder

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "puzzles": [
      {
        "startWord": "ANIL",
        "endWord": "CUED",
        "steps": 5,
        "solution": [
          "ANIL",
          "ARIL",
          "ARID",
          "IRID",
          "IRED",
          "CRED",
          "CUED"
        ],
        "solvable": true,
        "difficulty": "medium"
      }
    ],
    "count": 1,
    "difficulty": "medium",
    "html": "<html><head><title>Word Ladder</title><style>body {font-family: Arial, sans-serif; padding: 20px; max-width: 600px; margin: 0 auto;}h1 {text-align: center; color: #4CAF50;}.puzzle {background: #f5f5f5; padding: 25px; margin: 20px 0; border-radius: 10px;}.words {display: flex; justify-content: space-between; align-items: center; margin: 20px 0;}.word {font-size: 28px; font-weight: bold; letter-spacing: 3px; padding: 15px 25px; border-radius: 10px;}.start {background: #4CAF50; color: white;}.end {background: #2196F3; color: white;}.arrow {font-size: 30px; color: #999;}.steps {text-align: center; font-size: 14px; color: #666; margin-bottom: 15px;}.ladder {display: flex; flex-direction: column; align-items: center; gap: 10px; margin: 20px 0;}.rung {width: 150px; height: 40px; border: 2px dashed #ccc; border-radius: 5px; display: flex; align-items: center; justify-content: center; font-size: 18px; letter-spacing: 5px;}.hint {font-size: 13px; color: #888; font-style: italic; margin-top: 10px;}</style></head><body><h1>Word Ladder</h1><p style='text-align:center;'>Change one letter at a time to get from the first word to the last</p><div class='puzzle'><div class='steps'>Puzzle #1 - 5 steps</div><div class='words'><span class='word start'>ANIL</span><span class='arrow'>→</span><span class='word end'>CUED</span></div><div class='ladder'><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div><div class='rung'>_ _ _ _</div></div></div></body></html>",
    "image": {
      "imageName": "6f0f9e5e-ce0d-4570-a706-8fc5ccbfc948_wordladder.png",
      "format": ".png",
      "downloadURL": "https://storage.googleapis.com/apiverve/APIData/wordladder/6f0f9e5e-ce0d-4570-a706-8fc5ccbfc948_wordladder.png?GoogleAccessId=635500398038-compute%40developer.gserviceaccount.com&Expires=1766010731&Signature=FQwH%2FqXC0eYHgHqGKfBoEETrcXALoIpkf2z7HCkmYcFu2IgL2uMbCBi22tEsrlY3yOkksRuZ56C2685lLi98CWvgCF1J9UrYaAWjFtLesnHZ0i%2B0SWYIy5wZLWnVq4UrJDLZVrvSe8lh21mQJrduVY8QqV%2FI0sViUlnlndLMFUfhEQedKYAGRtmXjJlpl1YA9A9%2BtJoqRvMm4YStfJyLJmExPQKnPiRoP6EB6%2B8%2F1WUq5vH3%2BWglijVroxaJ%2BJy6kgQ8qTuVX9%2FzFi8R0DDHZtd0IpcTL8EBvNvHnjRPS4lZB%2Bm3k9GCxqGCnsj8pssu6ymtzGNEqA%2BBqAthODekWw%3D%3D",
      "expires": 1766010731681
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`puzzles`	array[1]		Array of word ladder puzzle objects with solutions
`startWord`	string	`"ANIL"`	Starting word for the puzzle transformation
`endWord`	string	`"CUED"`	Target word to transform the starting word into
`steps`	number	`5`	Number of letter-changing steps required to solve
`solution`Premium	array	`[ANIL, ...]`	Complete sequence of valid words forming solution path
`solvable`	boolean	`true`	Whether the puzzle has a valid solution path
`difficulty`	string	`"medium"`	Difficulty level of the puzzle (easy, medium, hard)
`count`	number	`1`	Total number of puzzles generated in response
`difficulty`	string	`"medium"`	Overall difficulty level of generated puzzles
`html`Premium	string	`"<html><head><title>Word Ladder</title><style>body {font-family: Arial, sans-serif; padding: 20px; max-width: 600px; margin: 0 auto;}h1 {tex…`	Printable HTML puzzle template with empty rungs
`image`Premium	object	`{...}`	The rendered puzzle image, present only when image=true is requested
`imageName`Premium	string	`"6f0f9e5e-ce0d-4570-a706-8fc5ccbfc948_wordladder.png"`	Unique filename for the generated puzzle image
`format`Premium	string	`".png"`	Image file format extension (e.g., .png)
`downloadURL`Premium	string	`"https://storage.googleapis.com/apiverve/APIData/wordladder/6f0f9e5e-ce0d-4570-a706-8fc5ccbfc948_wordladder.png?GoogleAccessId=635500398038-…`	Cloud storage URL to download the puzzle image
`expires`Premium	number	`1766010731681`	Unix timestamp when download URL expires

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Plan	Per month	Credits	Word Ladder Generator calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Compare all pricing tiers →

Call it from cURL — GET /v1/wordladder

No SDK to install — this is a plain HTTPS call to /v1/wordladder with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
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curl "https://api.apiverve.com/v1/wordladder" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/wordladder-apiSource, issues and the examples this page is built from.ReferenceWord Ladder Generator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/wordladdernpm APIVerve.API.WordLadderGeneratorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Node.js — GET /v1/wordladder

Install the Node.js SDK, then call the Word Ladder Generator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/wordladder

Node.js

const res = await fetch("https://api.apiverve.com/v1/wordladder", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/wordladderThe published Node.js client, versioned and signed.GitHubapiverve/wordladder-apiSource, issues and the examples this page is built from.ReferenceWord Ladder Generator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

APIVerve.API.WordLadderGeneratorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — GET /v1/wordladder

No SDK to install — this is a plain HTTPS call to /v1/wordladder with your key in the x-api-key header. Swap in a real key and it runs as-is.

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/wordladder",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

Also published for

@apiverve/wordladdernpm APIVerve.API.WordLadderGeneratorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from C# / .NET — GET /v1/wordladder

Install the C# / .NET SDK, then call the Word Ladder Generator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.WordLadderGenerator

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/wordladder");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.WordLadderGeneratorThe published C# / .NET client, versioned and signed.GitHubapiverve/wordladder-apiSource, issues and the examples this page is built from.ReferenceWord Ladder Generator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/wordladdernpm

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — GET /v1/wordladder

No SDK to install — this is a plain HTTPS call to /v1/wordladder with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/wordladder", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

Also published for

@apiverve/wordladdernpm APIVerve.API.WordLadderGeneratorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — GET /v1/wordladder

No SDK to install — this is a plain HTTPS call to /v1/wordladder with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/wordladder");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

Also published for

@apiverve/wordladdernpm APIVerve.API.WordLadderGeneratorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — GET /v1/wordladder

No SDK to install — this is a plain HTTPS call to /v1/wordladder with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/wordladder")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

Also published for

@apiverve/wordladdernpm APIVerve.API.WordLadderGeneratorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

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Word Ladder Generator API

Try it — live request, no key required

About the Word Ladder Generator API

What people use it for

Ways to call it

Other ways to use Word Ladder Generator

Questions.

Request parameters — GET /v1/wordladder

Optional

Authentication

Response — GET /v1/wordladder

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — GET /v1/wordladder

Resources

Also published for

Call it from Node.js — GET /v1/wordladder

Resources

Also published for

Call it from Python — GET /v1/wordladder

Resources

Also published for

Call it from C# / .NET — GET /v1/wordladder

Resources

Also published for

Call it from Go — GET /v1/wordladder

Resources

Also published for

Call it from PHP — GET /v1/wordladder

Resources

Also published for

Call it from Ruby — GET /v1/wordladder

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — Word Ladder Generator API

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