Base64 vs Hex Encoding: When to Use Each

At some point, most developers encounter a string that looks like this:

SGVsbG8gV29ybGQ=

Or this:

48656c6c6f20576f726c64

Both represent:

Hello World

Neither is encrypted.

Neither is compressed.

Neither is a hash.

They are simply different ways of representing the same underlying data.

The first uses Base64 encoding.

The second uses hexadecimal encoding, usually shortened to “hex.”

Both appear constantly in software development, APIs, security tools, networking protocols, and data formats.

Understanding the difference helps explain why some systems prefer Base64, why hashes are almost always displayed as hex, and why choosing the wrong format can unnecessarily increase storage and bandwidth requirements.

Encoding Is Not Encryption

Before comparing Base64 and hex, it’s important to understand what encoding actually does.

Encoding transforms data from one representation into another.

The purpose is usually compatibility or readability.

Consider:

Hello

Encoded as Base64:

SGVsbG8=

Encoded as hex:

48656c6c6f

Anyone can reverse either encoding instantly.

The original data has not been hidden.

This is why encoding should never be confused with encryption.

Why Encodings Exist

Computers work with binary data.

Everything ultimately becomes:

0s and 1s

Humans and many software systems prefer text.

Encoding provides a bridge between these worlds.

Instead of transmitting raw binary:

01001000
01100101
01101100
01101100
01101111

the data can be represented as text:

48656c6c6f

or:

SGVsbG8=

This makes storage, transmission, and debugging easier.

What Is Hex Encoding?

Hexadecimal is a base-16 numbering system.

Instead of ten symbols:

0-9

hex uses sixteen:

0-9
A-F

Each hexadecimal digit represents four bits.

Decimal	Binary	Hex
10	1010	A
11	1011	B
12	1100	C
13	1101	D
14	1110	E
15	1111	F

This makes binary data easier for humans to read.

Hex Example

The letter:

H

has an ASCII value of:

72

Binary:

01001000

Hex:

48

The word:

Hello

becomes:

48 65 6c 6c 6f

or:

48656c6c6f

Every byte becomes two hexadecimal characters.

What Is Base64 Encoding?

Base64 uses a larger character set.

Instead of sixteen symbols, it uses sixty-four.

A-Z
a-z
0-9
+
/

plus:

=

for padding.

Because Base64 has more available symbols, it can represent data more efficiently than hex.

Base64 Example

The same text:

Hello

becomes:

SGVsbG8=

The encoded result is shorter than the hexadecimal version.

This difference becomes more significant as data grows larger.

How Hex Works Internally

A byte contains:

8 bits

Hex splits those eight bits into two groups:

0100
1000

Each group becomes one hexadecimal digit.

4
8

Result:

48

This mapping is simple and direct.

One byte always becomes two hex characters.

How Base64 Works Internally

Base64 processes data differently.

Instead of working with four-bit chunks, it works with six-bit chunks.

Three bytes:

24 bits

become:

4 Base64 characters

This allows Base64 to store more information per character.

The result is improved efficiency.

Base64 vs Hex Size Comparison

One of the most important differences is expansion rate.

Hex

Every byte becomes:

2 characters

Expansion:

100%

A file doubles in size.

Base64

Every three bytes become:

4 characters

Expansion:

Approximately 33%

This is a significant improvement.

Example File Sizes

Original Data	Hex	Base64
100 KB	200 KB	133 KB
1 MB	2 MB	1.33 MB
10 MB	20 MB	13.3 MB

For large payloads, the difference becomes substantial.

Why Hashes Are Usually Displayed as Hex

Consider a SHA-256 hash:

e3b0c44298fc1c149afbf4c8996fb924
27ae41e4649b934ca495991b7852b855

Hex dominates in hashing because:

• Easy to read
• Easy to compare
• Fixed length
• Maps cleanly to bytes

Developers can often inspect hex values visually.

Base64 is less intuitive for this purpose.

Why Base64 Is Common in APIs

Many APIs transmit binary data through text-based protocols.

Examples include:

• JSON
• XML
• GraphQL

These formats expect text.

Binary data must be encoded.

A common approach is:

{
  "image": "SGVsbG8gV29ybGQ="
}

Base64 is preferred because it produces smaller payloads than hex.

Why JWT Tokens Use Base64

JSON Web Tokens (JWTs) contain encoded JSON data.

A JWT often looks like:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9

This uses Base64URL encoding, a variant of Base64 designed for URLs.

The format remains compact while remaining text-safe.

Why Cryptography Uses Both

Cryptographic systems frequently use both encodings.

Hex

Common for:

• Hashes
• Checksums
• Fingerprints
• Debugging

Base64

Common for:

• Certificates
• Public keys
• Encrypted payloads
• Tokens

The choice depends on the intended audience and storage requirements.

Human Readability

Hex is generally easier for humans to inspect.

Consider:

48 65 6c 6c 6f

Experienced developers can often recognise patterns.

Base64:

SGVsbG8=

is less visually obvious.

This is one reason debugging tools frequently display binary data in hexadecimal.

URL Compatibility

Standard Base64 includes:

+
/
=

These characters can create problems in URLs.

Base64URL replaces them with:

-
_

and often removes padding.

Example:

SGVsbG8

This makes the encoding URL-safe.

Hex does not have this issue because it only uses:

0-9
A-F

Base64 vs Hex

Feature	Base64	Hex
Number Base	64	16
Expansion Size	~33%	100%
Human Readability	Moderate	High
Common in APIs	Yes	Sometimes
Common for Hashes	Rarely	Very Common
URL Safe by Default	No	Yes
Debugging Friendly	Moderate	Excellent
Storage Efficiency	Better	Worse

Both formats remain useful.

They simply optimise for different goals.

When Should You Use Hex?

Hex is often the best choice when:

• Displaying hashes
• Showing checksums
• Debugging binary data
• Inspecting memory
• Working with low-level protocols

The direct relationship between bytes and hex digits makes analysis easier.

When Should You Use Base64?

Base64 is often the best choice when:

• Embedding binary data in JSON
• Sending files through APIs
• Encoding images
• Storing certificates
• Reducing payload size

The improved storage efficiency becomes increasingly important as data grows.

The Most Common Misconception

Many developers assume Base64 is a security feature.

It isn’t.

Consider:

SGVsbG8=

Anyone can decode it instantly.

Base64 provides representation, not protection.

The same is true for hex.

Neither encoding offers security.

Conclusion

Base64 and hex both solve the same fundamental problem: representing binary data using text.

Hex prioritises simplicity and readability. Every byte maps directly to two hexadecimal characters, making it ideal for hashes, checksums, debugging, and low-level inspection.

Base64 prioritises efficiency. By encoding more information into each character, it produces significantly smaller outputs and is commonly used in APIs, certificates, tokens, and file transmission.

In most cases the choice comes down to a simple question: do you care more about human readability or storage efficiency? If readability matters, hex usually wins. If size matters, Base64 is often the better option.