Hex to Base64 Converter

Hexadecimal (base-16) is extensively used to represent binary data in a compact, human-readable form, especially in low-level debugging, memory dumps, and cryptographic fingerprints. However, many web APIs and data transport mechanisms prefer Base64 for safe transmission over text-only channels. The Hex to Base64 converter takes a hex-encoded string—where each pair of hex digits represents one byte—and converts it into a Base64 string. Internally, the process involves parsing hex into raw bytes, then encoding those bytes under the standard Base64 alphabet with optional padding.

This transformation is crucial when interfacing legacy systems that output hex data with modern REST endpoints that accept Base64, or when embedding binary assets in data URIs for web content.

Each hex pair (00–FF) maps directly to a byte value (0–255). Base64 groups input bytes in blocks of three, producing four output characters from each block, using the A–Z, a–z, 0–9, +, / alphabet, with = padding for leftover bytes.

For web contexts, the converter can output URL-safe Base64 (replacing + with - and / with _) and omit padding if required by certain APIs.

Input should be a valid hex string: characters 0–9, A–F (case-insensitive), optionally separated by spaces or newlines. Non-hex characters are stripped before parsing. An odd number of digits triggers an error or pads with a leading 0 based on configuration.

The output is a standard Base64 string, including padding (“=”) by default. URL-safe variants and padding omission are configurable.

1. **Cleanup**: Strip all non-hex characters. 2. **Pairing**: Group digits into byte pairs. 3. **Byte Array**: Convert pairs to numeric bytes. 4. **Base64 Encode**: Apply standard Base64 algorithm to the byte array. 5. **Output**: Return the Base64 string.

Backend systems that receive hex-encoded keys or data from hardware devices can convert them to Base64 for storage in web-friendly databases. Frontend developers pulling hex fingerprints from APIs can Base64-encode them to embed as data URIs in CSS or HTML images.

In security tooling, converting hex dumps into Base64 simplifies piping binary_test vectors into JSON payloads for automated tests.

Hex parsing and Base64 encoding both run in linear time. For large data sets, use TypedArrays and process in chunks to avoid blocking.

Validate input length and content. Reject or sanitize odd-length hex strings. Limit maximum input size to mitigate denial-of-service.

`68656c6c6f` → `aGVsbG8=`