What input format does this expect?

A comma-separated list of decimal numbers from 0 to 255, like "137, 80, 78, 71, ...", optionally wrapped in square brackets (as if pasted from a code array literal).

What happens if one of my values is invalid?

The tool rejects the whole input with a specific error naming exactly which value was invalid — either because it wasn't a plain whole number, or because it was outside the valid 0-255 byte range.

Why does it check for a PNG signature after parsing?

Even if every individual number is a valid byte value, the resulting file might not actually be a PNG (wrong bytes, wrong order, truncated); checking the signature catches that before offering a misleading download.

Can I paste output from the PNG to Bytes converter directly?

Yes — this tool's input format is designed to exactly match that converter's output format, so round-tripping a file through both tools works without any manual editing.

Bytes to PNG Converter - Rebuild a PNG from a Decimal Byte List

Overview

Introduction

This tool rebuilds a downloadable PNG file from a pasted list of decimal byte values, entirely in your browser.

It's the exact reverse of the PNG to Bytes converter, designed to accept that tool's output format directly.

What Is Bytes to PNG Converter?

A client-side byte-list-to-PNG converter that parses a comma-separated (optionally bracket-wrapped) list of decimal numbers, validates every value is a legitimate byte (0-255), and assembles them into a raw byte array.

Once assembled, the bytes are checked against PNG's fixed 8-byte file signature before being offered as a download, so a mistyped or garbled list can't silently produce a corrupt file.

How Bytes to PNG Converter Works

The tool strips optional surrounding brackets, splits the remaining text on commas, and validates each resulting piece is a whole number string representing a value from 0 to 255 — rejecting the entire input with a specific error at the first invalid value found.

Once every value is confirmed valid, they're packed into a `Uint8Array` and checked against the PNG signature; only a signature match produces a downloadable result.

When To Use Bytes to PNG Converter

Use it to reconstruct a small PNG from a byte list you copied out of source code, documentation, or a hex/decimal dump.

It's also useful for round-trip testing: convert a PNG to bytes, then back, and confirm the result matches exactly.

Often used alongside PNG to Bytes Converter and Base64 to PNG Converter.

Features

Advantages

Runs entirely client-side; your data never leaves the browser.
Validates every individual value and the final PNG signature before offering a download.
Accepts both plain and bracket-wrapped list formats without extra editing.

Limitations

Impractical for large files, since a large byte list is tedious to paste and parse as plain text.
Any single malformed value in a long list stops the whole conversion, requiring you to fix and re-paste rather than skipping bad entries.

Examples

Rebuild a minimal PNG signature

Input

"137, 80, 78, 71, 13, 10, 26, 10"

Output

An 8-byte downloadable file matching the PNG signature

Every value parses as a valid byte and the resulting bytes match PNG's required signature.

Reject an out-of-range value

Input

"137, 80, 78, 71, 13, 10, 26, 300"

Output

An error: "Byte value 300 is out of range..."

300 exceeds the maximum valid byte value of 255, so the whole input is rejected with a specific message.

Best Practices & Notes

Best Practices

Paste output directly from the PNG to Bytes converter for a guaranteed-compatible format.
Double-check for stray characters (like a trailing comma or extra bracket) if you get a parsing error.

Developer Notes

The pure parsing logic mirrors the existing Base64 to PNG converter's structure — the same PNG signature check on the decoded bytes, but splitting and validating comma-separated decimal tokens instead of decoding base64 characters.

Bytes to PNG Converter Use Cases

Reconstructing a small PNG from a byte list found in source code or documentation
Round-trip testing a PNG to Bytes export
Recovering a PNG from a manually transcribed byte dump

Common Mistakes

Pasting a list with a value above 255 or a non-numeric token, which the tool correctly rejects rather than silently truncating or skipping.
Assuming any byte list works — the final bytes must actually form a valid PNG, starting with the correct 8-byte signature.

Tips

Use this together with the PNG to Bytes converter to verify a round trip reproduces the exact same file.
If your byte list is large, consider the Base64 converters instead for a far more compact text representation.

Bytes to PNG Converter