Convert KOI8 to UTF8
Convert KOI8 and KOI8-R encodings to UTF8 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 KOI8 to UTF8
- 1. Paste the KOI8 byte values. Enter the hex byte values from a KOI8 or KOI8-R source into the input pane. These bytes represent Cyrillic letters using a scheme designed to stay legible even after stripping the high bit.
- 2. Let the decoder apply the KOI8-R table. Every byte is mapped through the KOI8-R table, which places Cyrillic letters at positions chosen so basic transliteration remains readable if a system drops to 7-bit ASCII.
- 3. Copy the decoded UTF8 text. The output pane shows the correctly decoded Russian or other Cyrillic text. Copy it once the KOI8 bytes have been translated into standard UTF8 characters.
When to use Convert KOI8 to UTF8
Convert KOI8 to UTF8 decodes Cyrillic text stored in the KOI8 or KOI8-R encoding, once the dominant way Russian text was represented on Unix systems and early Russian internet services. This tool applies the correct byte-to-character mapping so text that shows up as scrambled Latin letters or boxes becomes readable Cyrillic.
- Reading an old Russian-language email archive. A mail archive from the late 1990s stores Russian messages in KOI8-R rather than UTF8. Decoding a sample message here confirms the encoding before you write a batch conversion script for the whole archive.
- Migrating a legacy Russian database. A database built on an older Unix system stored Cyrillic text fields in KOI8-R. Converting sample values here verifies your migration mapping before running it against production data.
- Debugging mojibake in a scraped Russian web page. A scraper pulled text from an older Russian site that never declared UTF8 and the result looks like random Latin characters. Decoding a snippet here confirms KOI8-R is the actual source encoding.
Examples
ASCII
Input
48 69
Output
Hi
Cyrillic
Input
F0 D2 C9 D7 C5 D4
Output
Привет
About the Convert KOI8 to UTF8 tool
Convert KOI8 to UTF8 runs as plain JavaScript in your browser tab, with no server behind it. Convert KOI8 and KOI8-R encodings to UTF8 encoding. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's UTF-8 Tools section, 69 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
There is nothing to configure. Provide the input and the result appears on its own. 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 Convert KOI8 to UTF8 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.