Aperi'Solve logo
Aperi'Solve v.3.3.1

Encodings & esolangs cheatsheet

You recovered something that is not yet the flag. Recognize the encoding and decode it. When unsure, paste it into CyberChef and run the Magic operation — it identifies and decodes most of the below automatically.

Base-N & hex

$ echo "SGVsbG8=" | base64 -d
$ echo "NBSWY3DP" | base32 -d
$ echo "48656c6c6f" | xxd -r -p                 # hex → bytes
$ echo "Q0lZ..." | base64 -d | xxd | head       # decode then inspect bytes
  • base58 / base62 / base85 (ascii85/z85) → CyberChef, or python3 -c "import base64;print(base64.b85decode(b'...'))".
  • base-N of unknown radix / bacon / atbash / rot-N → dcode.fr has a decoder per cipher; ROT13: tr 'A-Za-z' 'N-ZA-Mn-za-m'.

Numbers, Morse & Braille

  • Binary / decimal / octal ASCII → group by 8 (binary) and convert; CyberChef From Binary / From Decimal.
  • Morse (.- -...) → CyberChef From Morse Code, or dcode Morse.
  • Braille (⠓⠑⠇⠇⠕ or ./, patterns) → CyberChef From Braille.
  • A blob whose length is a perfect square → likely a QR bitmap; render it (below) rather than decode as text.

QR codes & barcodes

$ zbarimg --raw code.png                    # QR / EAN / Code128 / DataMatrix
$ zbarimg --raw -q code.png | xxd | head     # inspect binary QR payloads

Build a QR from a bitstring with an online QR-from-binary tool, or qrencode/segno to test hypotheses.

Ciphers & keys

  • XOR (single/multi-byte) → CyberChef XOR Brute Force, or xortool -c 20 payload.bin to recover the key length and key.
  • Vigenère / substitution → quipqiup (mono-alphabetic), dcode Vigenère (with/without key).

Esoteric languages

Recognize the source, then run an interpreter (mostly on tio.run):

  • Brainfuck — +-<>[]., only.
  • Whitespace — only spaces/tabs/newlines (pairs with SNOW findings).
  • Malbolge — dense, unreadable ASCII soup.
  • Piet — a picture: blocks of 20 colors (decode with npiet).
  • Ook! / Rockstar / Chef — word-based; identify via esolangs.org language list.

Chained encodings

Payloads are often wrapped twice (base64 → hex → gzip). Decode one layer, file/xxd the result, and repeat. CyberChef Magic with "Intensive mode" follows several layers for you.