ASCII Table Generator

Displays a complete reference chart of every ASCII code from 0 to 127 with its decimal, hexadecimal, octal, and binary representations side by side, and readable labels like <NUL> and <DEL> for the 33 non-printable control codes, filterable by a search box. A free online tool from Staaarter, right in your browser.

Runs locallyUpdated 2026-07-27

Overview

Introduction

Every text-based computing standard in use today traces back to the 128-character ASCII table, but few people have all 128 codes and their decimal, hex, octal, and binary forms memorized.

This tool lays out the complete table at once, with readable names for the non-printable control codes, and a filter box so you can jump straight to the code you need.

What Is ASCII Table Generator?

A static, complete reference chart of ASCII codes 0 through 127, showing each code's decimal, hexadecimal, octal, and binary representation alongside its character (or control-code label).

It requires no input by default; the full table renders immediately, and the optional filter box narrows it down when you're looking for one specific code.

How ASCII Table Generator Works

For each integer 0 through 127, the tool computes the hex, octal, and 7-bit binary representation, and looks up a readable label for the 33 codes (0-31 and 127) that have no printable glyph.

When a filter is entered, only rows where the decimal, hex, octal, binary, or character text contains that filter (case-insensitive) are kept in the rendered table.

When To Use ASCII Table Generator

Use it as a quick lookup while debugging serial protocols, parsing binary file formats, or writing code that manipulates raw byte values.

It's also a handy teaching aid for explaining how the same 128 values can be represented in four different number bases.

Features

Advantages

  • Shows all four common numeric representations for every code at once, no need to convert by hand or hop between separate converter tools.
  • Readable control-code labels make the otherwise-invisible codes 0-31 and 127 easy to identify.
  • The filter box makes it fast to find one specific code in a table of 128 rows.

Limitations

  • Covers only the 128 codes of standard 7-bit ASCII; extended 8-bit code pages and Unicode are out of scope.
  • The character column shows a bracketed label rather than an actual rendered glyph for the 33 non-printable codes, since they have none.

Examples

Filtering for the letter A

Input

A

Output

Dec 65, Hex 41, Oct 101, Bin 1000001, Char A

Typing "A" into the filter narrows the table to rows whose character, hex, or other column contains that text, including the uppercase letter A at code 65.

Looking up a control character

Input

NUL

Output

Dec 0, Hex 00, Oct 000, Bin 0000000, Char <NUL>

The null character at code 0 has no printable glyph, so it's shown with its standard three-letter abbreviation in angle brackets.

Best Practices & Notes

Best Practices

  • Use the filter box with a decimal, hex, or character value rather than scrolling through all 128 rows by eye.
  • Cross-reference with the PETSCII and ATASCII table generators when you need to compare how a platform-specific character set diverges from standard ASCII.

Developer Notes

Each row's hex, octal, and binary strings are generated with `code.toString(base)`, zero-padded to a fixed width per base (2 for hex, 3 for octal, 7 for binary) so columns stay visually aligned; the 33 non-printable labels are a hand-maintained lookup table of the standard ASCII control abbreviations.

ASCII Table Generator Use Cases

  • Looking up the exact hex or binary value of a character while debugging a protocol or file format
  • Teaching how the same 128 ASCII codes map across decimal, hex, octal, and binary
  • Identifying an unfamiliar control character abbreviation seen in a spec or log

Common Mistakes

  • Assuming a byte value above 127 will show up in this table; anything past 127 falls outside standard 7-bit ASCII entirely.
  • Confusing the octal column with decimal when reading a value quickly, always check which column you're in before using a number elsewhere.

Tips

  • The filter matches against every column at once, so searching "7" will surface hits from decimal, hex, octal, and binary columns alike.
  • Space (code 32) renders as a literal blank character cell in the table, that's expected, not a rendering error.

References

Frequently Asked Questions