Plain ASCII
Input
Hi
Result
4869
Capital H is 0x48 and lowercase i is 0x69, matching the ASCII table exactly.
Text Tools
String to Hex
Encode text into a hex string for transport, debugging, and inspection.
Start here Paste the exact text, including any trailing spaces or newlines you want to inspect.
Hex output
456e636f6465207468697320646576656c6f706572206e6f74652e
Understand the format
How String to Hex works
Hexadecimal shows the exact bytes behind a piece of text, which is the only reliable way to see invisible characters and encoding differences.
Two hex digits per byte
Text is converted to bytes with UTF-8, and each byte is printed as exactly two hexadecimal digits, from 00 to ff. ASCII characters occupy one byte each, so "Hi" becomes 4869. Characters outside ASCII take two to four bytes: the euro sign is e2 82 ac, and most emoji are four bytes.
Because the mapping is fixed at two digits per byte, the length of the hex string is always double the byte count. That gives you a quick integrity check: an odd number of hex characters means the value was truncated somewhere.
Why byte-level inspection settles arguments
Two strings that look identical on screen can differ in bytes. A non-breaking space (c2 a0) renders exactly like an ordinary space (20). A carriage return (0d) is invisible until it breaks a comparison. A zero-width space contributes bytes while occupying no visual width at all.
This is why hex output is the standard tool for diagnosing "but they are the same string" bugs in signature verification, checksum mismatches, and failing equality checks. The bytes cannot hide what the rendering does.
Step by step
How to use String to Hex
- Paste the exact text, including any trailing spaces or newlines you want to inspect.
- Read the hex output, working in pairs of digits, where each pair is one byte.
- Compare against the expected bytes, or against the hex of a known-good value.
- Look for 0d 0a line endings, c2 a0 non-breaking spaces, and a trailing 0a when a comparison unexpectedly fails.
Conversion uses the browser TextEncoder in the page, so the text you inspect is never uploaded.
Worked examples
String to Hex examples explained
An invisible trailing newline
Input
OK followed by a line break
Result
4f4b0a
The 0a is a line feed. This single byte is the most common reason a copied value fails to match a stored one.
Reference
Byte values worth recognising on sight
| Bytes | Character | Note |
|---|---|---|
| 20 | Space | The ordinary ASCII space. |
| 09 | Tab | Often introduced by copying from a table. |
| 0a | Line feed | The Unix line ending. |
| 0d 0a | Carriage return and line feed | The Windows line ending, and the cause of many diff and hash mismatches. |
| c2 a0 | Non-breaking space | Looks like a space, compares as a different character. Common when copying from web pages. |
| ef bb bf | Byte-order mark | An invisible prefix that breaks strict JSON and CSV parsers. |
| e2 82 ac | Euro sign | A reminder that one character is not always one byte. |
Practical Guide
How teams use String to Hex
Common use cases
- Inspect how text will be represented in systems that store or transmit hexadecimal.
- Prepare values for low-level protocol tests and fixtures.
- Compare two strings when invisible characters or spacing may be involved.
Checks before trusting the result
- The output depends on the character encoding, so compare like with like.
- Invisible characters such as line breaks change the result and are exactly what you are looking for.
- Keep the plain-text copy alongside the hex so a reviewer can validate the source.
Troubleshooting
Common mistakes and how to fix them
- Comparing this output with hex produced from a UTF-16 source.
- The byte sequences will differ for every character. Confirm both sides use UTF-8 before concluding the data is wrong.
- Assuming one character equals one byte when calculating lengths.
- Only for ASCII. Database column limits expressed in bytes will reject shorter strings that contain multi-byte characters.
- Pasting text from a rich-text editor and getting unexpected bytes.
- Editors substitute typographic quotes, en dashes, and non-breaking spaces. Paste through a plain-text step first.
FAQ
String to Hex questions, answered
Why is the hex string always an even length?
Every byte is printed as two digits, padded with a leading zero when needed. An odd length means characters were lost.
Is hexadecimal a form of encryption?
No. It is a printable representation of bytes and is trivially reversible, exactly like Base64 but 100% larger instead of 33%.
Why does one character produce several byte pairs?
UTF-8 is a variable-length encoding. ASCII takes one byte, most European and Middle Eastern scripts two, most CJK characters three, and emoji four.
Should the output be uppercase or lowercase?
Either is valid and they represent the same bytes. This tool emits lowercase, which is the more common convention in HTTP headers and Unix tooling.
How do I get the hex of a binary file?
Use a tool that reads the file bytes directly, such as xxd or a hex editor. Pasting binary content as text corrupts it before the conversion starts.
Go deeper
Specifications and guides
- Base64, Hex, and Percent-Encoding Compared — Three encodings, three jobs. How to tell them apart, when each is correct, and why none of them protects data.