Text to Hex

The Text to Hex tool converts any text into its hexadecimal byte representation. Hexadecimal is the compact, readable way to show binary data — each byte as two hex digits (00-FF). Convert \"Hello\" and get 48 65 6C 6C 6F (or 0x48 0x65 0x6C 0x6C 0x6F with prefixes, or 48656C6C6F continuous). Useful for debugging protocols, preparing test data, URL encoding foundations, generating hex literals for code, and any context where you need to see the exact byte sequence produced by a piece of text.

The tool handles ASCII (7-bit English) and UTF-8 (full Unicode, recommended) encoding. Output format is configurable: uppercase vs lowercase hex, with or without 0x prefix per byte, separated by space/comma/dash, or continuous without separators. Each byte is always 2 hex digits with leading zeros preserved for alignment. Unicode characters (emoji, accented letters, CJK) produce multi-byte UTF-8 sequences correctly. Reverse conversion via the companion Hex to Text tool. All processing runs in your browser — safe for sensitive text that shouldn\u2019t leave your machine.

Text-to-hex encoding steps:

1. Convert the text to a byte sequence using the chosen encoding:
- ASCII: each character\u2019s charCode (0-127) is one byte
- UTF-8: characters encode to 1-4 bytes via standard UTF-8 algorithm
2. For each byte, format as 2-digit hex using toString(16).padStart(2, \"0\")
3. Join bytes with the chosen separator and add any prefix per byte

JavaScript implementation: new TextEncoder().encode(text) returns Uint8Array of UTF-8 bytes. Each byte is then formatted with toString(16) and padded.

UTF-8 multi-byte encoding (automatic with TextEncoder):
- ASCII (0-127): 1 byte, same as ASCII
- 128-2047: 2 bytes (110xxxxx 10xxxxxx)
- 2048-65535: 3 bytes (1110xxxx 10xxxxxx 10xxxxxx)
- 65536+: 4 bytes (11110xxx 10xxxxxx 10xxxxxx 10xxxxxx)

Character count vs byte count: mismatch for UTF-8. \"café\" is 4 characters but 5 bytes (c=1, a=1, f=1, é=2). \"😀\" is 1 character but 4 bytes. The tool reports both.

Common hex output conventions:
- Programming language literal: 0x48, 0x69 (comma + prefix)
- URL encoding foundation: 48 69 (space-separated, no prefix) — actual URL encoding wraps in % signs
- BLOB/binary: 4869 (continuous, no prefix)
- Hex dump: 48 69 across columns with ASCII sidebar
- Network protocol: 48:69 (colon-separated, often lowercase)

The tool offers templates for these common formats plus custom configuration.

Uppercase vs lowercase: most technical contexts use uppercase (48 69) but some code style guides and hashes output lowercase (48 69). Purely cosmetic — both are valid.

Performance: conversion is O(n) and fast. Multi-megabyte text converts in milliseconds.

Size in hex: each byte becomes 2 hex characters. Plain ASCII text doubles in size when represented as hex (plus separators). UTF-8 text with non-ASCII characters may be 2-4x the original text\u2019s byte count due to multi-byte sequences.

Compared to a Python one-liner (text.encode().hex()), this tool is faster for one-off use and shows the character-to-byte mapping clearly. For automation, use the language built-in.

Compared to command-line xxd, this tool has a friendlier UI with configurable formats. xxd is ideal for hexdump pipelines; this tool is for interactive hex generation.

Compared to other online text-to-hex tools, this one correctly handles UTF-8 (many assume ASCII only) and provides templates for common use cases (C literals, URL encoding, protocol debugging).