Base64url encode

base64url-encode · version 1.0.0 · Other utilities · free, no key needed

Encode supplied UTF-8 text or hexadecimal bytes as base64url and return the encoded string.

Use when you need to: encode text as URL-safe base64 · convert hex bytes to base64url · make base64 safe for a URL.

Decide before calling

Read the versioned contract and the supported scope below. Reuse base64url-encode@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use base64url-encode@1.0.0 for encode text as URL-safe base64. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

• encode text as URL-safe base64
• convert hex bytes to base64url
• make base64 safe for a URL
• base64url encode UTF-8
• encode bytes without base64 padding
• create padded URL-safe base64

Not supported

• standard base64 with plus and slash
• decode base64url text
• encrypt or sign data

Behavior

• Exactly one of text or hex is supplied; text is encoded as UTF-8 and hex represents bytes.
• padding true appends RFC 4648 equals padding; padding false omits it.
• Hex input is case-insensitive and must have an even number of digits.
• Disclaimer: format transform only; provides no confidentiality, integrity, or authenticity.

Input

• text (string, optional): max length 12288
• hex (string, optional): max length 24576; pattern ^[0-9A-Fa-f]*$
• padding (boolean, required)

Output

• encoded (string, required): max length 16384; pattern ^[A-Za-z0-9_-]*={0,2}$
• standard_version (constant "RFC 4648 §5 (2006); RFC 7515 Appendix C (2015)", required)

Limits

• max input bytes: 12288
• max output bytes: 16384

Example

Request input:

{
  "text": "Hello?",
  "padding": false
}

Response:

{
  "result": {
    "encoded": "SGVsbG8_",
    "standard_version": "RFC 4648 §5 (2006); RFC 7515 Appendix C (2015)"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "base64url-encode",
  "version": "1.0.0",
  "input": {
    "text": "Hello?",
    "padding": false
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/base64url-encode/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello?","padding":false}'

The machine-readable contract is at /v1/tools/base64url-encode/versions/1.0.0.

CLI

node cli.mjs run base64url-encode 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

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