JWT Signer
Sign JSON claims as a JWT with HMAC or an RS256 private key using browser cryptography.
詳細な手順やよくある質問は、英語のみで提供されている場合があります。
ツール操作エリア
アカウント不要JWT Signer
These extra tools run in your browser. JWT signing keys and source text stay in this tab; treat generated tokens as credentials and never publish secrets.
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cURL converter: Translate common cURL requests into Python, JavaScript, and PHP.
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JWT signer: Sign JSON claims with HMAC or an RS256 PKCS#8 key.
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OpenAPI viewer: Inspect operations from JSON, YAML, OpenAPI, or Swagger files.
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.gitignore generator: Start a project ignore file from Node, Python, Java, Go, or React presets.
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CSS specificity calculator: Compare common ID, class, attribute, pseudo-class, and element selectors.
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Code screenshot generator: Render a code snippet locally and download a PNG.
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README + license generator: Draft a README and SPDX license notice for a project.
cURL to Python, JavaScript, and PHP
Python (requests)
import requests
response = requests.post("https://api.example.com/items", headers={"Content-Type":"application/json"}, data="{\"name\":\"sample\"}")
print(response.status_code, response.text)JavaScript (fetch)
const response = await fetch("https://api.example.com/items", { method: "POST", headers: {"Content-Type":"application/json"}, body: "{\"name\":\"sample\"}" });
console.log(response.status, await response.text());PHP (cURL)
$ch = curl_init("https://api.example.com/items");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json"]);
curl_setopt($ch, CURLOPT_POSTFIELDS, "{\"name\":\"sample\"}");
$response = curl_exec($ch);
curl_close($ch);JWT signer (HS256, HS384, HS512, RS256)
Signing does not validate token claims, issuer, audience, or authorization policy. Avoid production secrets in shared devices.
OpenAPI / Swagger viewer
.gitignore generator
node_modules/ .npm/ .env* dist/ coverage/ .DS_Store
CSS specificity calculator
Specificity (IDs, classes/attributes/pseudo-classes, elements): 1, 2, 3
This quick estimate follows common selector forms; :is(), :not(), and :has() argument specificity can vary from this simplified count.
Code screenshot generator
function greet(name) {
return `Hello, ${name}!`;
}README and license notice generator
README.md
LICENSE (SPDX notice)
The notice identifies the license but is not a substitute for the complete license text; include the official full text in distributed projects.