⌘ K
octal · text to octal · live

Convert text & numbers with Octal

Switch between text bytes, decimal integers, and base-8 — the encoding behind Unix file permissions, escape sequences, and classic C source.

Octal Converter
Input
19 B
1 lines
Output
75 B
1 lines
Status
ready
live
Ratio
3.95×
out/in
input · text
output · octal bytes
143 150 155 157 144 040 067 065 065 040 144 145 160 154 157 171 056 163 150
Quick Start

How to convert octal

Octal uses digits 0-7 — each digit covers 3 bits, so a byte fits in 3 octal digits. Perfect for chmod, escape codes, and bit-fields.

  1. 01

    Pick conversion

    Text bytes ↔ octal triplets, or whole decimal integers ↔ base-8.

    Bytes flow through TextEncoder/TextDecoder for predictable UTF-8 semantics — emoji, surrogate pairs, and combining marks all encode losslessly.

    modeUTF-8TextEncoderlosslesslive
    mode · raw bytestext-to-octal · UTF-8
    text · decimal
    loaded · UTF-8MIME · ready
  2. 02

    Paste input

    Bytes are space-separated. Numbers can include big integers — BigInt handles them.

    Hash and signature operations call crypto.subtle from the Web Crypto API, so output matches OpenSSL / Node bit-for-bit.

    inputWeb Cryptosubtledeterministiclive
    input · optionsdata · live
    chmod 755 deploy.sh
    options applied · livelive
  3. 03

    Read result

    Triplets keep leading zeros so each byte stays 3 digits — easy to grep.

    Options re-run instantly through useEffect + useMemo — switching URL-safe mode or padding doesn’t re-encode from scratch.

    livememoisedoptionsinstantreactive
    out · encodedoct · ready
    143 150 155 157 144 …
    encoded · livelossless
  4. 04

    Copy or download

    Drop straight into chmod, printf, or a C string literal.

    Copy uses the Async Clipboard API; downloads ship via Blob with the appropriate MIME (text/plain, image/png, …) so external tools recognise them.

    exportclipboardblobMIME-correctclient-side
    ✓ · copiedready · done
    ✓ Copied
    shipped · ready to shipsuccess
Pro tips

Encoding without surprises

Always UTF-8 first

Use TextEncoder / TextDecoder for bytes ↔ string conversion. btoa alone breaks on non-ASCII.

URL-safe vs standard Base64

Standard uses +, /, =; URL-safe swaps to -, _, no padding. Don’t mix them.

Hashes aren’t passwords

SHA-256 is fast; that’s good for fingerprints, bad for passwords. Use bcrypt / argon2 for credentials.

Watch padding rules

Some decoders are strict about = padding, others auto-pad. If round-trips fail at exactly 1 or 2 bytes, check padding.

Use Web Crypto for keys

Generate cryptographic keys via crypto.subtle, never Math.random. The latter is predictable.

JWT decode ≠ verify

Decoding a JWT just splits and base64-decodes. Verification needs the issuer’s public key / shared secret.

Related toolsText to HexASCII ConverterBCD ConverterBase32 ConverterBase64 EncoderHex Dump Viewer
Use Cases

When to use octal

Unix permissions, escape sequences, retro programming.

chmod values

755, 644, 700 — read these as rwx triples in octal. Output round-trips losslessly with the matching decoder — both run client-side, so end-to-end testing happens in a single tab. Encoding flows through TextEncoder for predictable UTF-8 semantics.

RFC-compliant

C escape strings

\150\151 embeds 'hi' inside a string literal. Web Crypto's subtle.digest produces output that matches OpenSSL, GPG, and Node's crypto module byte-for-byte. That makes the result trustworthy as a content fingerprint, ETag, or integrity check.

OpenSSL-matched

PDP-11 / vintage CPU

Octal was the native human encoding of 12/24-bit words. Pairs cleanly with HMAC, JWT, and signed-URL workflows where bit-level correctness matters. The browser's crypto stack is FIPS 140-validated in Chrome and Firefox, so it's production-grade.

lossless

umask defaults

Translate 022 ↔ 0644 result mode quickly. Output uses canonical RFC 4648 / 7515 alphabets so curl, openssl, and any standards-compliant decoder accept it as input. URL-safe variants drop padding for tokens that travel in query strings.

byte-identical

AWK / sed scripts

Embed non-printable bytes via \NNN sequences. Heavy hashing runs through useMemo so large inputs don't block typing. PBKDF2, bcrypt, and Argon2 expose configurable cost factors — tune for your threat model, not the default.

spec-grade

Old kernel docs

Linux fcntl flags & ioctl numbers ship in octal. Same input plus same options always yields identical bytes. That's the foundation for content-addressed storage (IPFS, Git, S3 ETags) and means the output is safe to commit to fixtures.

production-ready
FAQ

Frequently asked questions

A byte's max value is 377 octal (255 decimal). Padding ensures every byte takes exactly 3 columns — easier to align and parse.
On output, no — bytes are bare triplets. On decimal→octal, the raw digits print so you can prepend 0 or 0o yourself.
BigInt octal is unsigned in this tool. Strip the sign or two's-complement first if you need signed encoding.
Yes. Whitespace is split with /\s+/ so tabs, newlines, and runs of spaces all work.
No — octal conversion runs locally in your browser.
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