Compilers that run in your browser.

How it works

A real compiler and simulator, not an editor with a run button.

1. Write

   Edit in a full code editor with highlighting and autocomplete. Your files are saved to your account.

   PROCESS (clk)
   BEGIN
     IF rising_edge(clk) THEN
       cnt <= cnt + 1;
     END IF;
   END PROCESS;

2. Run

   Compile and simulate in one click. See waveforms for VHDL and result tables for T-SQL.

         0    10   20   30 ns
   clk   ▁▀▁▀▁▀▁▀▁▀▁▀▁▀▁▀
   cnt   0 │ 1 │ 2 │ 3 │ 4
   Simulation finished at 40 ns

3. Fix

   Errors point at the exact line. Press "Explain error" for a plain-language explanation of what to change.

   error: 'cnt' is not declared
     counter.vhd:14:5
   Explain error:
   Line 14 uses cnt, but it is
   never declared. Add a signal
   before BEGIN:
     SIGNAL cnt : INTEGER;