<input type=number>: min, max, step

Numeric inputs in HTML

<input type="number" name="age" min="13" max="120" step="1" />
<input type="number" name="price" min="0" step="0.01" />
<input type="range" name="volume" min="0" max="100" step="5" value="50" />

• type="number" — text-style input with up/down spinners. Decimal allowed with step="0.01" (or any fractional step).
• type="range" — a slider. No text typing. Good for "set volume" / "pick a year between 1900-2026."

Pydantic parallel

class SignupForm(BaseModel):
    age: int = Field(ge=13, le=120)   # >= 13, <= 120
    price: Decimal = Field(ge=0)

Your HTML min="13" max="120" mirrors the Pydantic ge=13 le=120. Same validation, two layers: browser blocks bad input, backend re-validates. Never trust browser-only — XSS can submit anything.

Negative numbers

min="-100" works. step="any" allows arbitrary precision.

Why not type="text" + pattern="\d+"?

You could. But type="number" gives you:

1. Number-pad keyboard on mobile (matters more than you think).
2. Up/down arrow spinners on desktop.
3. Native validation tooltip in the user's language.

type="text" would give you none of these.