Replace Hex Digits
Substitute certain hexadecimal digits with other digits. 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 Replace Hex Digits
- 1. Paste the source hex. Drop your hex string or value list into the input pane. Substitution runs across everything you paste, so long dumps work as well as a single short number.
- 2. Set Find digit and Replace with. Put the nybble to hunt for in Find digit and its stand-in under Replace with. Swapping a for f turns a1a2 into f1f2, changing every occurrence in one deterministic pass.
- 3. Respect list boundaries with Separator. If the input holds several values, enter their delimiter as the Separator so replacements apply within each value and the punctuation between them stays exactly as it was.
- 4. Copy the substituted text. Copy the rewritten hex from the output pane. Running the tool again with the two digits swapped back undoes the change, provided the replacement digit did not already appear in the input.
When to use Replace Hex Digits
Replace Hex Digits substitutes one nybble for another everywhere it occurs in your hex data. Think of it as find and replace scoped to hexadecimal characters, useful for correcting systematic transcription errors, normalizing conventions and constructing controlled variations of hex test inputs.
- Fixing an OCR transcription artifact. A scanned datasheet's hex tables came through OCR with every b read as 8. Once you spot the pattern, one replacement pass across the extracted text repairs the entire table.
- Anonymizing dumps before sharing. Before pasting a memory dump into a public issue tracker, you want a distinctive digit pattern in device serials masked. Substituting those nybbles hides the identifier while keeping the dump's structure.
- Creating controlled corruption for tests. A decoder should detect single-nybble corruption in its input. Replacing one digit value throughout a valid payload manufactures a corrupted twin whose difference from the original is precisely known.
Examples
Replace a with f
Input
a1a2
Output
f1f2
About the Replace Hex Digits tool
Replace Hex Digits is a free online tool that works entirely inside your web browser. Substitute certain hexadecimal digits with other digits. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 108 Hex utilities on EditSafely. Each one does a single job well, and all of them follow the same rule: your input stays on your machine.
You can shape the output with 3 settings, including Find digit, Replace with and Separator, and the result refreshes the moment you change one. A worked example further down the page shows exactly what the tool produces for a real input.
Because nothing leaves your device, the tool is suitable for sensitive content such as internal documents, credentials or customer data. It also responds instantly, since every keystroke is handled on your own machine rather than by a remote API.
Frequently asked questions
Does Replace Hex Digits 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.