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HEX to Octal

Convert hexadecimal to octal — base 16 to base 8 through clean binary.

100% Free No signup Privacy-friendly Binary & Number Tools
Updated Sep 2026

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How to use HEX to Octal

  1. Enter the hex value — e.g. 1ED (case doesn't matter, drop any 0x prefix).
  2. Read the octal instantly: 1ED → 755.
  3. Convert several values at once by separating them with spaces.
  4. Click “Copy result” — prefix with 0o or a leading 0 as your language requires.

What is HEX to Octal?

A hex to octal converter translates between the two compact bases programmers use: base 16 down to base 8. Hex FF is octal 377; hex 1ED is octal 755. There is no digit-for-digit shortcut between them — hex digits are 4 bits and octal digits are 3, and 4 and 3 don't align — so the honest route is hex → binary → regroup in threes → octal.

That regrouping is fiddly to do by hand (expand FF to 11111111, split as 11 111 111, pad, read 377), which is why a converter beats mental math the moment values get longer than a byte.

About the HEX to Octal

Enter a hex value and its octal equivalent appears instantly — the binary regrouping happens internally and exactly, at any length.

When you need it: translating a file mode you have in hex (0x1ED) into the chmod octal every Unix tool expects (755), converting byte values between a hex dump and an octal-speaking legacy format or escape sequence (hex 41 → octal 101 → \101 → the letter A), and cross-checking number-systems homework that asks for both notations.

Case-insensitive input, invalid digits flagged by token, all in your browser. Octal to Hex runs the reverse; Hex to Binary shows the intermediate bit pattern if you want to see the regrouping yourself.

Frequently Asked Questions

Hex digits carry 4 bits, octal digits 3 — the groupings don't line up. You must expand to binary and regroup: FF → 11111111 → 11 111 111 → 377.
377 — the largest one-byte value (decimal 255). Old Unix code and escape sequences write it \377 where modern code writes 0xFF.
Some APIs and languages report the mode field as a hex integer (0x1ED). Converting to octal recovers the familiar chmod form: 0x1ED = 755.
Octal 101 — the letter A's code (decimal 65). Hex dumps say 41; C string escapes say \101; both are the same byte.
Hex, in almost all modern contexts — it aligns with bytes (2 digits each). Octal survives specifically for Unix permissions and a few escape-sequence traditions; use it there and hex everywhere else.

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