Baudot / ITA2 Teleprinter Code
Encode and decode text with ITA2 — the International Telegraph Alphabet No. 2, the 5-bit character code best known as Baudot, used by teleprinters from the 1920s through to early computers and news-wire services. Each character is a 5-bit code (so only 32 codes exist), which is too few for letters and digits, so ITA2 uses two character sets toggled by shift codes: LTRS (11111) for letters and FIGS (11011) for figures (digits and punctuation). The encoder emits a shift code only when the set changes; the decoder tracks the current set. Enter text to turn it into its 5-bit teleprinter codes and back, with the full LTRS/FIGS table shown for reference. Everything runs locally in your browser.
Encode (text → 5-bit codes)
Decode (5-bit codes → text)
ITA2 code table
The math. ITA2 assigns each character a 5-bit code (values 0–31). Because 32 codes cannot hold 26 letters plus 10 digits and punctuation, the code splits into two sets selected by two shift codes: 11111 switches to LTRS (letters) and 11011 switches to FIGS (figures); the receiver stays in that set until the next shift, exactly like a typewriter's Shift Lock. A handful of codes are shared by both sets — 00100 (space), 00010 (carriage return), and 01000 (line feed) — so they need no shift. The encoder starts in LTRS and emits a shift only when the next character's set differs from the current one; the decoder starts in LTRS and applies shifts as it reads. 00000 is null (no character). Encoding handles A–Z (upper-cased), digits 0–9, space, CR, LF, and common punctuation; characters outside the ITA2 alphabet are skipped. The figures set shown here is the international printable convention; a few figure codes (notably the bell / "who-are-you" signals) vary between national variants. Pairs with the Bacon, Tap Code, Morse Code, and ASCII tools. Everything runs locally — nothing leaves your browser.