Hex Endianness Converter
Convert a hex value between big-endian and little-endian — one general-purpose tool for the byte-order flip, whichever direction you need.
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: Endianness — Wikipedia
How Endianness Conversion Works
Split the value into 2-digit byte pairs, then write those pairs back in the opposite order. Since this operation is its own reverse, the same calculation converts big-endian to little-endian or little-endian to big-endian — the direction is determined by what the input already is, not by anything the calculator needs to know in advance.
Endianness Terms at a Glance
| Term | Byte order | Common on |
|---|---|---|
| Big-endian | Most significant byte first | Network protocols, some file formats |
| Little-endian | Least significant byte first | x86, ARM (most desktop/mobile CPUs) |
| Byte swap | Reversing whichever order it's currently in | Same operation either direction |
Where Endianness Conversion Actually Comes Up
Moving Data Between Network and Host Byte Order
Any time data crosses the boundary between a network protocol (typically big-endian) and a little-endian host system, the multi-byte fields need converting in one direction or the other.
network packet field <-> host variable
Porting Binary File Handling Between Platforms
Reading or writing a binary format originally designed on hardware with different native endianness than the system you're working on now.
legacy big-endian format on a little-endian machine
General-Purpose Debugging of a Byte-Order Issue
When you're not sure which specific conversion you need yet, this one tool handles the actual byte-swap step while you work out the rest of the debugging.
flip bytes, then check if the value makes sense
Why Use This Calculator Instead of Doing It by Hand
- One calculator for both conversion directions, since the operation is symmetric
- Handles values of any byte length, not just a fixed 16/32/64-bit width
- Runs entirely in your browser — nothing you type gets sent anywhere
- Avoids the easy hand-reversal mistake of swapping nibbles instead of whole bytes
Limitations
- Reverses whole bytes only — an odd number of hex digits gets a leading zero nibble added first, which can shift byte boundaries if that wasn't intended.
- Doesn't enforce a specific register width — use the 16/32/64-bit Hex Endian Converter pages if you need padding locked to a specific size.
Frequently Asked Questions
Why is this one converter instead of separate big-to-little and little-to-big tools?
Because reversing byte order is symmetric — the exact same operation converts big-endian to little-endian and little-endian to big-endian, so one calculator covers both directions.
How do I know which direction I actually need?
Check the source and destination of your data — if you're reading network data into a little-endian system (most desktops/phones), that's big-to-little; writing a little-endian value out to a network protocol is little-to-big. Either way, this converter's output is the same regardless of which direction you're thinking about it.
Does this work for any bit width?
Yes — it operates on whatever number of bytes you provide, not a fixed 16/32/64-bit width. For a converter locked to a specific width, see the 16-bit, 32-bit, and 64-bit Endian Converter pages.
What's the difference between endianness and bit-level ordering?
Endianness is about byte order (which byte comes first); bit order within each byte never changes in a byte swap. The two are entirely separate concepts, even though both relate to how data is arranged.