Join Hex Numbers
Merge several hex values together and form a larger hex. Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use Join Hex Numbers
- 1. Paste the pieces. Enter the hex fragments to combine, such as 12 34 56, into the input pane. Order matters, since the pieces are concatenated left to right into one longer value.
- 2. Tell it the Separator. Set Separator to whatever currently divides your fragments, a space, comma or newline. The tool strips that delimiter and fuses the digits, so 12 34 56 becomes 123456.
- 3. Copy the merged hex. One continuous hex string appears in the output pane. Copy it into your code, calculator or converter. The companion split tool cuts it back into chunks whenever you need the pieces again.
When to use Join Hex Numbers
Join Hex Numbers concatenates a list of hex values into a single larger one, removing whatever separator kept them apart. Byte-oriented tools love spitting out space-separated pairs, while APIs and calculators usually want one unbroken string, and this tool bridges those two worlds in a single paste.
- Rebuilding a value from hexdump bytes. You copied four space-separated bytes out of an xxd dump and need them as one 32-bit constant for your source code. Joining them produces the literal to paste after 0x.
- Assembling a key from split segments. A hardware token prints its 128-bit key as eight groups of four digits for readability. Join the groups into the continuous string the provisioning API actually accepts.
- Condensing packet fields for comparison. Wireshark shows a MAC address or session ID as colon-separated bytes, but your log files store it unseparated. Merging the bytes lets you grep the logs for the exact value.
- Preparing input for a hash or checksum check. A vendor emailed a firmware checksum as spaced byte pairs. Join them into one string so it string-compares cleanly against the digest your build pipeline printed.
Examples
Join values
Input
12 34 56
Output
123456
With separator
Input
ab cd
Output
ab:cd
About the Join Hex Numbers tool
Join Hex Numbers runs as plain JavaScript in your browser tab, with no server behind it. Merge several hex values together and form a larger hex. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's Hex Tools section, 108 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
You can shape the output with the Separator setting, and the result refreshes the moment you change it. 2 worked examples further down the page show exactly what the tool produces for real inputs.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Does Join Hex Numbers cost anything?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
No data leaves your device. The whole tool is JavaScript that runs inside your browser tab, so there is no upload, no server-side processing and no log of what you did. If you disconnect from the internet after the page loads, it keeps working.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
Nothing to install and no account needed. Open the page in any up-to-date browser, including on a phone or tablet, and the tool is ready.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.