Base64 vs hexadecimal encoding: which should you use for binary data?
Use Base64 for data interchange, APIs, and anywhere size matters. Use hex for hashes, debugging, and anywhere readability matters. They're not competitors. They're different tools for different jobs, and any competent developer should be comfortable with both.
Base64 and hexadecimal both encode binary data as text, but they serve different purposes. Base64 packs 6 bits per character (64-character alphabet) and expands data by about 33%. Hex packs 4 bits per character (16-character alphabet) and expands data by exactly 100%. The choice comes down to whether you prioritize compactness or readability.
By TechCompare · Updated
How this is calculated
Base64 is the standard for embedding binary data in JSON, email attachments (MIME), data URIs in CSS, and JWT tokens. Hex is preferred for cryptographic hashes (SHA-256 fingerprints), memory dumps, color codes, and anywhere you want to see individual byte values at a glance. A SHA-256 hash in hex is 64 characters, while the same hash in Base64 is 44 characters. For large payloads (megabytes of binary), Base64's 33% overhead saves significant bandwidth and storage compared to hex. For debugging and inspection, hex wins because each pair of characters is exactly one byte.
Verdict
The overhead gap is real and measurable: Base64 packs 6 bits per character for 33% expansion, hex packs 4 bits for 100% expansion. A SHA-256 hash shrinks from 64 hex characters down to 44 in Base64, which is why JWT and MIME lean on it. Hex stays relevant for hashes, memory dumps, and color codes where two characters per byte makes the value readable at a glance.