Convert Octal to ASCII

Three input styles, mixed within the same input freely: bare numbers separated by whitespace/commas (110 145 154), C-style escape sequences (141142143), and 0-prefixed octals (0110 0145). The regex parser picks up each token independently – you can paste a mix of all three.

If your entire input (after stripping whitespace) matches 3 or 4 octal digits, the tool reads it as a Unix file mode. Each digit is decomposed into a read-write-execute triplet: 7 = rwx, 6 = rw-, 5 = r-x, 4 = r–, etc. A 4-digit mode adds special bits in front: 4 = setuid, 2 = setgid, 1 = sticky. So 04755 decodes as rwsr-xr-x (setuid bit replaces the user’s x with s). The panel only appears when the input parses as a permission mode.

The valid range is octal 0 through 377 (decimal 0-255), which covers ASCII (0-127) and Latin-1 extended (128-255). Anything above 0377 is rejected as invalid and counted in the “invalid” stats. For Unicode codepoints beyond Latin-1, you’d need a different encoding – UTF-8 in octal would be multi-byte sequences which this tool doesn’t synthesize.

Octal 012 = newline (LF), 011 = tab, 015 = carriage return, 000 = null. In raw output mode these are invisible – your decoded text might look truncated when it’s actually fine. “Show control chars” mode renders them as n, t, r, so you can see exactly what bytes are there. Useful when debugging unexpected output.

Switch direction to ASCII → Octal, then pick encode style “C escape”. Input abc outputs 141142143 which is the literal escape form valid in C, C++, Python, and most modern languages. Paste directly into a string literal.

Octal 110 = decimal 72 = ASCII ‘H’. Decimal 110 = octal 156 = ASCII ‘n’. Crucial distinction – octal and decimal look identical without context. Many systems prefix octal with 0 (so 0110 is octal, 110 is decimal) but this convention isn’t universal. This tool treats bare 110 as octal because the context is an octal-to-ASCII tool.

Mainly Unix file permissions (chmod 0755), C/C++ string escape sequences (\NNN for arbitrary bytes), some legacy mainframe formats, and very old programming languages (early FORTRAN, PDP-11 assembly). Most modern computing has migrated to hexadecimal because it maps cleanly to bytes (2 hex digits = 1 byte), whereas octal doesn’t (3 octal digits = 9 bits ≠ 8 bits).

Convention. A single byte is 8 bits = 0-255 = 0-377 in octal (3 octal digits cover 0-377 perfectly). 1 and 2 octal digits can encode smaller values, but if you want fixed-width like hex’s “always 2 digits per byte”, octal’s equivalent is 3 digits with leading zeros. C-escape sequences use exactly that – 00 through 377.

No. All parsing, conversion, and permission decoding runs in your browser using vanilla JavaScript. Open DevTools → Network and confirm zero requests fire after the page loads – even when you Convert or switch modes. Safe for proprietary log dumps or sensitive permission audits.

Yes. Total bundle is under 22 KB. Once loaded, disconnect and keep converting. Useful for sysadmin work on air-gapped machines where C escape decoding and chmod analysis both come up.