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Base64 Decoder

Decode Base64 back to text, handling URL-safe and whitespace.

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Overview

Decodes Base64 to text. Auto-detects URL-safe alphabet and strips whitespace.

Features

Auto-detects URL-safe.
Strips whitespace.
Reports invalid char positions.

Use cases

Decoding a JWT payload.
Reading a PEM block.

API reference

POST /api/v1/tools/base64

Encode a string to Base64 or decode Base64 back to text. Supports URL-safe (RFC 4648 §5) and PEM-style line-wrap on encode.

Returns: The encoded or decoded Base64 string, plus the byte count of the input.

Parameters

Name	Type	Required	Default	Description
`action`	string (encode\|decode)	Yes	—	Whether to encode or decode.
`input`	string	Yes	—	The text to encode, or the Base64 string to decode.
`urlSafe`	boolean	No	`false`	Produce (or accept) the URL-safe alphabet with - and _ instead of + and /.
`lineWrap`	boolean	No	`false`	On encode, wrap output into lines of lineWrapWidth characters (PEM-style).
`lineWrapWidth`	number	No	`76`	Line width when lineWrap is true. Default 76 (RFC 1421).

Example

curl -X POST https://data-migration-tools.com/api/v1/tools/base64 \
  -H "Content-Type: application/json" \
  -d '{"action":"encode","input":"hello world","urlSafe":true}'

See the full API reference for all examples and error codes.