ASCII Code to Text Converter

Decoding ASCII numeric codes back to characters

Every ASCII character has a corresponding decimal code between 0 and 127. To decode a sequence of ASCII codes back to text, you look up the character for each decimal number and concatenate them. Code 72 is H, code 101 is e, code 108 is l, code 108 is l, code 111 is o - so the code sequence 72 101 108 108 111 decodes to Hello.

This tool automates that lookup. Paste a space-separated list of decimal ASCII codes and the converter outputs the corresponding string. Non-printable characters (codes 0-31 and 127) are rendered as visible placeholders rather than being silently omitted or invisible in the output.

The same character-code relationship appears in many programming contexts. JavaScript's String.fromCharCode(), Python's chr(), and C's direct cast from integer to char all perform this same mapping. This tool gives you the same result without writing a single line of code.

Uses in protocol parsing

Network protocols often transmit text data as raw byte sequences. When a debugging tool shows those bytes as decimal integers rather than characters, you need to convert them to read the actual message. SMTP, HTTP/1.1, FTP, and many other text-based protocols send headers as sequences of ASCII bytes. Log lines from packet captures sometimes show payload bytes as comma-separated or space-separated decimal values.

Paste the decimal byte sequence directly here to read the text content without writing a decode script. This is faster when you are working through a debugging session or reading a log file and need to quickly check a single field.

Embedded systems and serial communication protocols also frequently log data as integer byte sequences. If your device logs character data as decimal values for diagnostics, converting those values here lets you read the logged messages directly.

Expected input format

Enter ASCII code points as decimal integers separated by spaces. Commas between values are also accepted and stripped before processing. The input 72 101 108 108 111 32 87 111 114 108 100 decodes to Hello World.

Values outside the standard ASCII range (0-127) are accepted. Codes from 128 to 255 correspond to extended ASCII or Latin-1 characters and are treated as their Unicode equivalents. Codes above 255 return the corresponding Unicode character. Negative numbers and non-integer values are flagged as invalid.

Frequently asked questions