Text Processingflags: g

Base64 String

Match Base64-encoded strings, including proper padding with = and == characters.

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Available in

JSSupported

JavaScript / ECMAScript

Browser-native RegExp. Default if you don't pick.

PYSupported

Python (re)

CPython stdlib `re`. Unicode-aware `\w` and `\d` by default.

GOSupported

Go (RE2)

Linear-time matching. No backreferences or lookarounds.

Pattern

regexengine-agnostic
(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?   (flags: g)

Raw source: (?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?

How it works

The pattern matches groups of 4 Base64 characters ((?:[A-Za-z0-9+\/]{4})*) then allows the trailing partial group: 3 chars + one =, or 2 chars + ==. This enforces valid Base64 padding rules.

Examples

Input

SGVsbG8gV29ybGQ=

Matches

  • SGVsbG8gV29ybGQ=

Input

dGVzdA==

Matches

  • dGVzdA==

Input

not!base64!@

No match

—

Common use cases

  • •Detecting Base64 payloads in HTTP bodies or headers
  • •Config file secret detection (base64-encoded credentials)
  • •Email MIME part extraction
  • •JWT payload decoding pipelines
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