Convert UTF8 to FSS-UTF
Convert UTF8 encoding to FSS-UTF encoding. 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 Convert UTF8 to FSS-UTF
- 1. Paste the UTF-8 text. Type or paste the text you want expressed under its historical name, such as the single letter A, into the input pane.
- 2. Choose a Separator. Enter the character placed between each output byte to match whatever format an old document or system labels its FSS-UTF byte sequences with.
- 3. Copy the FSS-UTF hex bytes. The output pane shows each character's byte value in hex, identical to what modern UTF-8 would produce, since FSS-UTF is the original name for the same scheme.
When to use Convert UTF8 to FSS-UTF
Convert UTF8 to FSS-UTF produces byte sequences under the original File System Safe UTF Transformation Format name that Ken Thompson and Rob Pike gave the encoding before it became today's UTF-8 standard. Since the two are byte-identical, this is mainly for historical accuracy rather than a real conversion.
- Matching terminology in a historical codebase. You are contributing to a project descended from early Plan 9 or Unix code that still calls its byte layout FSS-UTF in comments and documentation, and want a reference value to match.
- Writing a talk on Unicode's early history. You are preparing a presentation on how UTF-8 was invented and want to show attendees a live example labeled with the scheme's original 1992 name.
- Annotating a retro-computing archive. You maintain an archive of historical Unix documentation and want to generate accurate FSS-UTF byte examples to accompany the original design notes you are preserving.
Examples
Convert
Input
A
Output
41
About the Convert UTF8 to FSS-UTF tool
Convert UTF8 to FSS-UTF is a free online tool that works entirely inside your web browser. Convert UTF8 encoding to FSS-UTF encoding. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 69 UTF-8 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 the Separator setting, and the result refreshes the moment you change it. 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
Is Convert UTF8 to FSS-UTF free to use?
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?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
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?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
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.