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decimal-to-ascii

Decimal to ASCII reverses the encoding: 65 → A, 97 → a, 32 → space. Useful for decoding character-code arrays, recovering text from C-style int arrays, and reading hex-dump-derived sequences. The ZTools Decimal to ASCII converter accepts any whitespace / comma-separated decimal list and outputs the resulting text, with warnings for out-of-range or non-printable codes.

Use cases​

Decode a char array​

C array {72, 101, 108, 108, 111} → "Hello". Useful for reading firmware dumps.

Read a manually-typed hex/decimal sequence​

Forensics or CTF: hex/decimal numbers; convert to readable text.

Inspect serialised data​

Some binary formats use ASCII-decimal length prefixes — decode to verify.

How it works​

  1. Paste decimal codes — Comma, space, or newline-separated. Tool parses each as integer.
  2. Validate — Codes 0-127 are pure ASCII. 128-255 extended. Above 255 (Unicode) toggles to UTF-8 mode.
  3. Convert — String.fromCharCode per code. Output assembled.
  4. Display — Resulting text. Non-printable codes shown as escape sequences (\n, \t) or control symbols.

Examples​

Input: 72, 101, 108, 108, 111

Output: "Hello".

Input: 65, 66, 67, 32, 49, 50, 51

Output: "ABC 123".

Input: 9, 10

Output: \t\n (tab, newline).

Frequently asked questions​

What if a code is out of range?

0-127 is pure ASCII. 128-255 is locale-dependent. Above 255 is Unicode (toggle UTF-16 / UTF-32 mode).

Non-printable codes?

Codes 0-31 are control characters. Tool shows them as \n, \t, etc., or special symbols (NUL, SOH).

Privacy?

All in browser.

Tips​

  • For pure ASCII text, codes stay 32-126 (printable). Anything else hints at non-ASCII or control characters.
  • For roundtrip verification, convert text → decimal → text and confirm match.

Try it now​

The full decimal-to-ascii runs in your browser at https://ztools.zaions.com/decimal-to-ascii — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-06 · Author: Ahsan Mahmood · Edit this page on GitHub