How is this different from Convert a String to Decimal?

Decimal conversion shows each character's Unicode code point, one number per character. This tool shows the actual UTF-8 byte sequence, where a single character outside the ASCII range produces multiple bytes.

Why do some characters produce more than one byte?

UTF-8 encodes code points above 127 using 2, 3, or 4 bytes depending on their value, so a single emoji or accented letter typically expands into several byte values in the output.

String to Bytes Converter - Text to UTF-8 Bytes Online

Overview

Introduction

Understanding exactly how many bytes a piece of text actually takes up, and what those bytes are, matters for network payloads, storage limits, and debugging encoding issues.

This tool shows the real UTF-8 byte sequence.

What Is String to Bytes Converter?

A converter that encodes text to UTF-8 and lists each resulting byte's decimal value, space-separated.

It runs entirely client-side as part of this site's String Tools collection, so nothing you paste is ever uploaded to a server.

How String to Bytes Converter Works

The tool encodes the input with the browser's TextEncoder, producing a Uint8Array of UTF-8 bytes, then formats each byte as a decimal number.

The transformation happens synchronously in JavaScript the moment you type, with no network round trip involved.

When To Use String to Bytes Converter

Use it to see exactly how many bytes a string of text occupies, or to compare against a Convert a String to Decimal output to see where multi-byte characters expand.

It's a fast way to get the answer without opening a code editor, a REPL, or writing a one-off script just to check.

Often used alongside Bytes to String Converter and String to Hex Converter.

Features

Advantages

Shows the true UTF-8 byte-level representation, not just code points.
Directly measures the byte size relevant to network and storage limits.

Limitations

Byte count can be noticeably larger than character count for non-ASCII text, which can be surprising if you expected them to match.

Examples

Encoding text with an emoji

Input

Hi 👋

Output

72 105 32 240 159 145 139

The ASCII characters take one byte each, while the wave emoji expands into four UTF-8 bytes.

Best Practices & Notes

Best Practices

Use this tool's output specifically when checking against a byte-limited constraint like a database column or network payload size.

Developer Notes

Encoding uses `new TextEncoder().encode(input)`, the standard Web API for UTF-8 byte-accurate encoding, rather than a manual bit-shifting implementation.

String to Bytes Converter Use Cases

Checking a string's exact UTF-8 byte size against a storage or network limit
Debugging an encoding mismatch by inspecting raw byte values
Learning how UTF-8 encodes multi-byte characters

Common Mistakes

Assuming byte count always equals character count; they diverge for any non-ASCII text.

Tips

Use Convert Bytes to a String to decode the result back to text.

String to Bytes Converter