Slice Unicode
Quickly extract a part from Unicode data. 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 Slice Unicode
- 1. Paste the text to slice. Enter the Unicode text you want a piece of into the input pane. The tool counts positions by code point, not byte, so accented letters and symbols count as one unit each.
- 2. Set Start index and End index. Enter where the slice begins and ends in code points. Negative values count backward from the end, so minus one refers to the last character, matching common array slice conventions.
- 3. Copy the extracted piece. The tool returns the characters between your start and end index, exclusive of the end. Copy the extracted substring once it matches the portion you needed.
When to use Slice Unicode
Slice Unicode extracts a substring between two code point indexes, with negative index support for counting from the end. It exists because JavaScript's own slicing works on UTF-16 code units, which silently breaks apart characters outside the basic plane like many emoji.
- Pulling a fixed-width prefix from mixed-script text. A product catalog needs the first five characters of a title as a preview snippet, and some titles contain accented or CJK characters. Slicing by code point avoids cutting a character in half.
- Trimming the last few characters off a string. A filename with an emoji suffix needs that suffix removed before saving. Using a negative end index drops the trailing characters cleanly without corrupting the emoji's surrogate pair.
- Testing a custom substring function against emoji edge cases. You are writing your own slicing logic and want a known-correct reference result for text containing multi-code-point emoji before comparing it against your implementation.
- Extracting a middle section from a log line. A structured log entry has a fixed layout and you need just the middle field, which sometimes contains non-ASCII values. Slicing by start and end index isolates that field reliably.
Examples
Slice code points 0..4
Input
café ☕ time
Output
café
About the Slice Unicode tool
Slice Unicode runs as plain JavaScript in your browser tab, with no server behind it. Quickly extract a part from Unicode data. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's Unicode Tools section, 98 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 2 settings, including Start index (code points, negatives allowed) and End index (code points, negatives allowed), 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.
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
Is Slice Unicode 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.