# Six-digit code input

> Six boxes for a one-time code that jump to the next one by themselves, with the active box gently pulsing.

- Category: [Inputs](https://library.aimran.es/components/inputs)
- Built with: HTML + CSS
- Live editor: https://library.aimran.es/blocks/uv-in2-otp
- Library: AIMRAN Library (https://library.aimran.es), free, no sign-up, by Aimran Oukham

## Where to use it

This is the screen after “We sent you a code”: two-factor login in a banking app, confirming a phone number at sign-up or checking an email before a password reset. Each box takes one digit, letters are ignored and backspace goes back a box. An OTP input in HTML, CSS and a little JavaScript.

Pasting a full code from an SMS only fills the first box in this version, so add paste handling if your users copy codes a lot. On phones, the numeric keypad opens by itself, which makes typing quick.

## Code

### HTML

```html
<div class="uv-in2o"><input maxlength="1" inputmode="numeric"><input maxlength="1" inputmode="numeric"><input maxlength="1" inputmode="numeric"><input maxlength="1" inputmode="numeric"><input maxlength="1" inputmode="numeric"><input maxlength="1" inputmode="numeric"></div>
```

### CSS

```css
.uv-in2o {
  --c1: #0071e3;
  --c2: #8ec5ff;
  --s: 16px;
  /* tamaño */
  --k: 1;
  /* velocidad */
  --fg: #1d1d1f;
  /* texto */
  --bg: #f5f5f7;
  /* fondo */
}

.uv-in2o {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  color: var(--fg);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  gap: .45em;
}

.uv-in2o input {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  width: 2.4em;
  height: 3em;
  padding: 0;
  text-align: center;
  font-size: calc(var(--s) * 1.15);
  font-weight: 650;
  color: var(--fg);
  background: color-mix(in srgb,var(--fg) 5%,transparent);
  border: 0;
  outline: 0;
  border-radius: .7em;
  box-shadow: inset 0 0 0 1.6px color-mix(in srgb,var(--fg) 10%,transparent);
  transition: all calc(0.3s / var(--k)) cubic-bezier(.34,1.56,.64,1));
}

.uv-in2o input:focus {
  box-shadow: inset 0 0 0 2px var(--c1),0 0 0 4px color-mix(in srgb,var(--c1) 14%,transparent);
  scale: 1.08;
  animation: uv-in2o calc(1.6s / var(--k)) cubic-bezier(.25,.1,.25,1) infinite;
}

.uv-in2o input.full {
  color: var(--c1);
  box-shadow: inset 0 0 0 1.8px color-mix(in srgb,var(--c1) 55%,transparent);
}

@keyframes uv-in2o {
  0%,100% {
    box-shadow: inset 0 0 0 2px var(--c1),0 0 0 4px color-mix(in srgb,var(--c1) 14%,transparent);
  }
  50% {
    box-shadow: inset 0 0 0 2px var(--c1),0 0 0 8px color-mix(in srgb,var(--c1) 6%,transparent);
  }
}
```

### JavaScript

```js
document.querySelectorAll(".uv-in2o").forEach(el => {
  const ins=[...el.querySelectorAll("input")];ins.forEach((i,k)=>{i.addEventListener("input",()=>{i.value=i.value.replace(/\D/g,"");i.classList.toggle("full",!!i.value);if(i.value&&ins[k+1])ins[k+1].focus()});i.addEventListener("keydown",e=>{if(e.key==="Backspace"&&!i.value&&ins[k-1])ins[k-1].focus()})})
});
```

### React

```tsx
// @ts-nocheck: setup() es JavaScript del DOM sin tipos, el mismo de la pestaña JS.
import { useEffect, useRef, type CSSProperties } from "react";

const css = `
.uv-in2o {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  color: var(--fg);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  gap: .45em;
}

.uv-in2o input {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  width: 2.4em;
  height: 3em;
  padding: 0;
  text-align: center;
  font-size: calc(var(--s) * 1.15);
  font-weight: 650;
  color: var(--fg);
  background: color-mix(in srgb,var(--fg) 5%,transparent);
  border: 0;
  outline: 0;
  border-radius: .7em;
  box-shadow: inset 0 0 0 1.6px color-mix(in srgb,var(--fg) 10%,transparent);
  transition: all calc(0.3s / var(--k)) cubic-bezier(.34,1.56,.64,1));
}

.uv-in2o input:focus {
  box-shadow: inset 0 0 0 2px var(--c1),0 0 0 4px color-mix(in srgb,var(--c1) 14%,transparent);
  scale: 1.08;
  animation: uv-in2o calc(1.6s / var(--k)) cubic-bezier(.25,.1,.25,1) infinite;
}

.uv-in2o input.full {
  color: var(--c1);
  box-shadow: inset 0 0 0 1.8px color-mix(in srgb,var(--c1) 55%,transparent);
}

@keyframes uv-in2o {
  0%,100% {
    box-shadow: inset 0 0 0 2px var(--c1),0 0 0 4px color-mix(in srgb,var(--c1) 14%,transparent);
  }
  50% {
    box-shadow: inset 0 0 0 2px var(--c1),0 0 0 8px color-mix(in srgb,var(--c1) 6%,transparent);
  }
}
`;

// Interacción en JavaScript del DOM: la misma que en la pestaña JS.
// eslint-disable-next-line @typescript-eslint/no-explicit-any
function setup(el: any) {
  const ins=[...el.querySelectorAll("input")];ins.forEach((i,k)=>{i.addEventListener("input",()=>{i.value=i.value.replace(/\D/g,"");i.classList.toggle("full",!!i.value);if(i.value&&ins[k+1])ins[k+1].focus()});i.addEventListener("keydown",e=>{if(e.key==="Backspace"&&!i.value&&ins[k-1])ins[k-1].focus()})})
}

export default function In2Otp() {
  const ref = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const el = ref.current?.firstElementChild;
    return el ? setup(el) : undefined;
  }, []);

  return (
    <>
      <style>{css}</style>
      <div
        ref={ref} style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <div className="uv-in2o"><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /></div>
      </div>
    </>
  );
}
```

## Prompt for AI assistants

Paste this into ChatGPT, Claude, Cursor, v0 or Lovable to adapt the block to your stack (Tailwind, Vue, Svelte…):

````text
I want to add the “Six-digit code input” block (Inputs) from AIMRAN Library to my project.

## What it is
Six boxes for a one-time code that jump to the next one by themselves, with the active box gently pulsing.

## Chosen settings
- Main color: #0071e3
- Secondary color: #8ec5ff
- Size: 16px (from 12 to 24px)
- Speed: 1x (from 0.5 to 2x)

## What I need
1. Add it to my project with the same look and animation as the reference code: same sizes, colours, radii, shadows, timings and easing.
2. It is built with plain HTML and CSS (the reference wraps it in a React component with its CSS). If my project uses something else (Vue, Svelte, Astro, plain HTML…), translate it without losing any behaviour. If I use Tailwind, turn the styles into classes; if not, keep the CSS in its own file.
3. Expose the settings above as props (or CSS variables) with those values as defaults.
4. Make it work well on phones: nothing that depends only on hover, touch targets of at least 44 px and no overflow on 320 px screens.
5. Make it look right in light and dark mode.
6. Keep it accessible: semantic HTML, roles and aria-* where needed, visible focus and keyboard support.
7. Respect prefers-reduced-motion: with reduced motion, no big animations but the same end result.

## Reference code
```tsx
// @ts-nocheck: setup() es JavaScript del DOM sin tipos, el mismo de la pestaña JS.
import { useEffect, useRef, type CSSProperties } from "react";

const css = `
.uv-in2o {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  color: var(--fg);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  gap: .45em;
}

.uv-in2o input {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  width: 2.4em;
  height: 3em;
  padding: 0;
  text-align: center;
  font-size: calc(var(--s) * 1.15);
  font-weight: 650;
  color: var(--fg);
  background: color-mix(in srgb,var(--fg) 5%,transparent);
  border: 0;
  outline: 0;
  border-radius: .7em;
  box-shadow: inset 0 0 0 1.6px color-mix(in srgb,var(--fg) 10%,transparent);
  transition: all calc(0.3s / var(--k)) cubic-bezier(.34,1.56,.64,1));
}

.uv-in2o input:focus {
  box-shadow: inset 0 0 0 2px var(--c1),0 0 0 4px color-mix(in srgb,var(--c1) 14%,transparent);
  scale: 1.08;
  animation: uv-in2o calc(1.6s / var(--k)) cubic-bezier(.25,.1,.25,1) infinite;
}

.uv-in2o input.full {
  color: var(--c1);
  box-shadow: inset 0 0 0 1.8px color-mix(in srgb,var(--c1) 55%,transparent);
}

@keyframes uv-in2o {
  0%,100% {
    box-shadow: inset 0 0 0 2px var(--c1),0 0 0 4px color-mix(in srgb,var(--c1) 14%,transparent);
  }
  50% {
    box-shadow: inset 0 0 0 2px var(--c1),0 0 0 8px color-mix(in srgb,var(--c1) 6%,transparent);
  }
}
`;

// Interacción en JavaScript del DOM: la misma que en la pestaña JS.
// eslint-disable-next-line @typescript-eslint/no-explicit-any
function setup(el: any) {
  const ins=[...el.querySelectorAll("input")];ins.forEach((i,k)=>{i.addEventListener("input",()=>{i.value=i.value.replace(/\D/g,"");i.classList.toggle("full",!!i.value);if(i.value&&ins[k+1])ins[k+1].focus()});i.addEventListener("keydown",e=>{if(e.key==="Backspace"&&!i.value&&ins[k-1])ins[k-1].focus()})})
}

export default function In2Otp() {
  const ref = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const el = ref.current?.firstElementChild;
    return el ? setup(el) : undefined;
  }, []);

  return (
    <>
      <style>{css}</style>
      <div
        ref={ref} style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <div className="uv-in2o"><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /><input maxLength={1} inputMode="numeric" /></div>
      </div>
    </>
  );
}
```

Give me the complete final code, ready to paste, and tell me in one line where to put it in my project.
````