Tools / Base64 Decoder
Base64 & Base32 Decoder
Paste an encoded string and this tool will decode it automatically. Use Multi-layer Base64 mode to unwrap nested encodings — it keeps decoding until the output stops being valid Base64 or a flag appears.
Mode
Paste encoded text above to see the result.
How it works
Base64 encodes binary data as printable ASCII using a 64-character alphabet (A–Z, a–z, 0–9, +, /). The output is padded to a multiple of four characters with =. Base32 uses only uppercase letters and digits 2–7, making it safe for case-insensitive systems.
Some CTF challenges nest multiple layers of Base64 — encode once, then encode that output again, and so on. The Multi-layer mode handles this automatically.
Challenges solved with this tool: picoCTF 2023 — Repetitions, picoCTF 2023 — ReadMyCert.