Java Integer to Hex Converter
Convert a Java int to its hexadecimal string form — the same conversion Integer.toHexString() performs, including how negative values are represented.
Built by
Swapnil SanghviFull-Stack Web Developer & WordPress Developer
Swapnil Sanghvi is a full-stack web and WordPress developer, UI designer, and full-time freelancer who builds and maintains Hex Calculator.
Further reading: hex — Stack Overflow
How Java Converts an Integer to Hex
Integer.toHexString() converts an int to base 16 using lowercase digits with no prefix. For a positive value the result matches the number directly; for a negative int, Java shows the full 32-bit two's-complement bit pattern instead of a minus sign.
Where Java Integer to Hex Actually Comes Up
Formatting a Color or Hash Value
Converting an ARGB color int or a computed hash value to its hex form for logging, display, or generating a hex color string.
Integer.toHexString(color)
Logging a Computed Value in Hex
Converting a bitmask or checksum value to hex before logging it, since hex is often easier to cross-reference against documentation than decimal.
log.debug("value = 0x" + Integer.toHexString(v))
Building a Hex-Encoded Identifier String
Converting a numeric ID or counter to hex to build a compact string identifier for display or storage.
id -> compact hex identifier
Why Use This Calculator Instead of Doing It by Hand
- Matches the digit output of Integer.toHexString() for positive values
- Runs entirely in your browser — nothing you type gets sent anywhere
- Saves manually converting and formatting the output
- Useful for checking expected output before writing test assertions
Limitations
- Adds a 0x prefix and uses uppercase digits — Java's toHexString() returns lowercase digits with no prefix.
- Only non-negative input is supported here — a negative Java int's unsigned hex bit pattern isn't reproduced by this converter.
Frequently Asked Questions
How do I convert an int to hex in Java?
Call Integer.toHexString(value) — Integer.toHexString(255) returns "ff", lowercase with no prefix.
What does Integer.toHexString(-1) return?
"ffffffff" — Java treats the int's 32 bits as unsigned for this conversion, so a negative int shows its full two's-complement bit pattern rather than a minus sign.
How do I convert a long instead of an int?
Use Long.toHexString(value) instead — the equivalent method for the 64-bit long type, which similarly shows the unsigned bit pattern for a negative long.
How do I pad the result to a fixed width?
Use String.format("%08X", value) instead of toHexString(), which lets you specify both the digit count and letter case in one call.