encoding

Base64 Encoder / Decoder API Reference

Encode any UTF-8 string to Base64 or decode a Base64 string back to plain text. Supports standard Base64 (RFC 4648) and URL-safe Base64 (uses - and _ instead of + and /). Detects and reports malformed input.

Endpoint

POST/api/base64

Full URL: https://quickhelp.dev/api/base64

Request

Content-Type: application/json. No authentication required for the anonymous free tier (30 req/min per IP).

Field	Type	Required	Description
input	string	Yes	The string to encode or decode
mode	default	No	encode — convert plain text to Base64; decode — convert Base64 to plain text
charset	default	No	standard uses + and /; url-safe uses - and _ (safe for URLs and filenames)

Response

Returns application/json. On error, returns a JSON object with an error string field and an appropriate HTTP status code.

Field	Type	Description
output	string	—
valid	boolean	—
encoding	enum	—
byte_length	number	Byte length of the input (encode) or decoded output (decode)
error	optional	—

Example

Encode text to Base64

curl

curl -X POST https://quickhelp.dev/api/base64 \
  -H 'Content-Type: application/json' \
  -d '{"input":"Hello, World!","mode":"encode","charset":"standard"}'

Request body

{
  "input": "Hello, World!",
  "mode": "encode",
  "charset": "standard"
}

Response

{
  "output": "SGVsbG8sIFdvcmxkIQ==",
  "valid": true,
  "encoding": "standard",
  "byte_length": 13
}

Error codes

Status	Meaning
200	Success — result in response body
400	Bad request — invalid input; error field describes the problem
404	Tool not found
429	Rate limit exceeded (30 req/min anonymous, 300 req/min free key)
500	Internal server error — transient; retry with exponential back-off

OpenAPI spec

The full OpenAPI 3.1 specification for all tools is available at /openapi.json. Import it into Postman, Insomnia, or any OpenAPI-compatible client to get all endpoints with schema validation automatically.