ASCII to Byte

Convert ASCII text into a list of byte values (0–255)

Input

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Output

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What is ASCII to Byte

Last reviewed: April 18, 2026

ASCII (American Standard Code for Information Interchange) is a 7-bit character encoding that defines 128 characters, forming the historical basis for most modern encodings.

ASCII to Byte walks each character in your input and emits its Latin-1 byte value (0–255). For multi-byte Unicode characters, only the low byte is preserved, matching String.prototype.charCodeAt & 0xff semantics.

The tool is commonly used when building fixtures for low-level protocols, serial handshakes, or embedded firmware where input needs to be expressed as explicit byte arrays.

Why use it

Build byte-array fixtures for Arduino, ESP32, and Raspberry Pi projects.
Prepare test vectors for TCP / UDP protocol handlers.
Double-check that a string fits in the 0–255 ASCII range.
Generate shell-ready byte lists for `printf '\x...'` commands.
Produce payloads for cryptographic unit tests.

Features

Emits space-separated decimal bytes
Truncates Unicode to low byte for clarity
Matches String.charCodeAt semantics
Handy for embedded / firmware fixtures
Zero-upload ASCII to Byte pipeline, nothing touches a server

How to use ASCII to Byte

Paste text. Drop any ASCII or Latin-1 string into the input.
Run. Each character becomes a byte value between 0 and 255.
Copy bytes. Use the list in your embedded project or test.

Example (before/after)

Text

Hi!

Bytes

72 105 33

Common errors

Emoji returns surprising values

Multi-byte Unicode characters are truncated to their low byte.

Fix: Use Character to ASCII if you need the full Unicode code point.

Expecting hex output

This tool returns decimal bytes.

Fix: Use Text to Hex if you need hexadecimal byte listings.

FAQ

How does it handle emoji?

They are truncated to their low byte — use Char to ASCII for full code points.

Is the separator space or comma?

Space. Copy and replace if you need comma-separated values.

Does it support hex output?

No — use Text to Hex for hex byte output.

Can I round-trip through Byte to ASCII?

Yes, for pure Latin-1 input. Unicode input will change after truncation.

Is data uploaded?

No — all work is done locally in your browser.

Related tools

Pair this with Byte to ASCII, Text to Hex, and Text to Binary for round-trip workflows. You can also browse the full Encoders & Decoders category for more options.

Byte to ASCII

Convert space or comma separated byte values (0–255) to ASCII text

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Decimal to ASCII

Convert a list of decimal character codes to ASCII / Unicode text

ASCII Code to Character

Turn a list of ASCII / Unicode code points back into readable text

Character to ASCII Code

Convert each character in a string to its ASCII / Unicode code point

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