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Base64 to Hex: Complete Conversion Guide

Convert Base64 to hexadecimal and back. Learn when to use hex instead of Base64, and how to convert between the two formats in JavaScript, Python, and online.

Base64 is great for text-safe transmission. But sometimes you need hexadecimal instead. Hex is easier to read, debug, and compare. Every byte becomes exactly two characters. No padding, no special characters. Here is how to convert between the two.

Why Convert Base64 to Hex?

Hex makes binary data human-readable at a glance:

Debugging hash values. SHA256, MD5, and other hashes are typically displayed in hex. If you get a Base64-encoded hash from an API, convert it to hex to compare.
Inspecting binary payloads. Each pair of hex digits is one byte. Easy to count offsets and spot patterns.
Firmware and embedded systems. Many tools output hex dumps. Base64 is rare in low-level contexts.

JavaScript: Base64 to Hex

function base64ToHex(base64) {
  // Decode Base64 to raw bytes
  const binary = atob(base64);
  const bytes = new Uint8Array(binary.length);
  for (let i = 0; i < binary.length; i++) {
    bytes[i] = binary.charCodeAt(i);
  }
  // Convert each byte to 2-char hex
  return [...bytes].map(b => b.toString(16).padStart(2, '0')).join('');
}

base64ToHex("SGVsbG8="); // "48656c6c6f" (Hello)

JavaScript: Hex to Base64

function hexToBase64(hex) {
  const bytes = new Uint8Array(hex.length / 2);
  for (let i = 0; i < hex.length; i += 2) {
    bytes[i / 2] = parseInt(hex.slice(i, i + 2), 16);
  }
  return btoa(String.fromCharCode(...bytes));
}

hexToBase64("48656c6c6f"); // "SGVsbG8="

Python: One-Liner

import base64, binascii

# Base64 to Hex
decoded = base64.b64decode("SGVsbG8=")
hex_str = binascii.hexlify(decoded).decode()
# "48656c6c6f"

# Hex to Base64
raw = bytes.fromhex("48656c6c6f")
b64 = base64.b64encode(raw).decode()
# "SGVsbG8="

Base64 vs Hex: When to Use Which

Feature	Base64	Hex
Size increase	33% larger	100% larger
Characters	A-Z, a-z, 0-9, +, /	0-9, A-F
Human readable	No	Partially (byte-pairs)
Best for	Network transfer, JSON, data URIs	Hashes, debugging, firmware

Need to encode or decode Base64?

Try our free online tool. Paste Base64 or hex and get instant results.

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