# Build Mode

Zig has four build modes:

To add standard build options to a build.zig file:

build.zig
const std = @import("std");

pub fn build(b: *std.Build) void {
    const optimize = b.standardOptimizeOption(.{});
    const exe = b.addExecutable(.{
        .name = "example",
        .root_module = b.createModule(.{
            .root_source_file = b.path("example.zig"),
            .optimize = optimize,
        }),
    });
    b.default_step.dependOn(&exe.step);
}

This causes these options to be available:

-Doptimize=DebugOptimizations off and safety on (default)-Doptimize=ReleaseSafeOptimizations on and safety on-Doptimize=ReleaseFastOptimizations on and safety off-Doptimize=ReleaseSmallSize optimizations on and safety off

# Debug

Shell

$ zig build-exe example.zig

Fast compilation speed
Safety checks enabled
Slow runtime performance
Large binary size
No reproducible build requirement

# ReleaseFast

Shell

$ zig build-exe example.zig -O ReleaseFast

Fast runtime performance
Safety checks disabled
Slow compilation speed
Large binary size
Reproducible build

# ReleaseSafe

Shell

$ zig build-exe example.zig -O ReleaseSafe

Medium runtime performance
Safety checks enabled
Slow compilation speed
Large binary size
Reproducible build

# ReleaseSmall

Shell

$ zig build-exe example.zig -O ReleaseSmall

Medium runtime performance
Safety checks disabled
Slow compilation speed
Small binary size
Reproducible build