Webflags: gi

Data URI

Match base64-encoded data URIs, including the MIME type and the base64 payload.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("data:[\\w\\/+\\-.]+(?:;[\\w=\\-]+)*;base64,[A-Za-z0-9+\\/=]+", "gi");
const input = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"data:[\w\/+\-.]+(?:;[\w=\-]+)*;base64,[A-Za-z0-9+\/=]+", re.IGNORECASE)
input_text = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`(?i)data:[\w\/+\-.]+(?:;[\w=\-]+)*;base64,[A-Za-z0-9+\/=]+`)
	input := `data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

data:[\w\/+\-.]+(?:;[\w=\-]+)*;base64,[A-Za-z0-9+\/=]+   (flags: gi)

Raw source: data:[\w\/+\-.]+(?:;[\w=\-]+)*;base64,[A-Za-z0-9+\/=]+

How it works

Starts with data:, then a MIME type (word chars, slashes, plus, hyphen, dot), optional parameters, then ;base64, and the base64 payload (letters, digits, +, /, =).