ASCII Codes to String
Convert space-separated ASCII code values back to readable text instantly — with validation of the 0–127 range. Free, client-side ASCII decoder.
🔒 100% Client-Side Processing
Your data is processed entirely in your browser and never transmitted to any server.
0 / 100M Limit
Common Use Cases
Decoding device output
Convert the decimal byte dumps from Arduino serial monitors and hardware logs back into readable text.
Solving encoded puzzles
Translate ASCII-code sequences from CTFs and classroom exercises into their message.
Frequently Asked Questions
- What input does the decoder expect?
- Whitespace-separated decimal values in the 0–127 ASCII range, e.g. "72 101 108 108 111" decodes to "Hello". Values outside that range are flagged with a validation message rather than silently mis-decoded.
- Why is my input rejected as invalid?
- The decoder validates each token: non-numeric text or codes above 127 trigger the error listing the offending values. Check for stray punctuation or Unicode code points, which need a different decoder.
- How do I convert ASCII codes to characters in JavaScript?
- String.fromCharCode(72, 105) returns "Hi" — pass one or more code points and it maps each back to its character. Paste codes here first to confirm the expected string before writing the code.
- Is my data private when I use this tool?
- Yes. This tool runs entirely in your browser using client-side JavaScript — nothing you type is transmitted to, logged by, or stored on any server. You can safely process confidential text, tokens, or code.