# Odometer number
> A huge figure whose digits roll into place with a spring when it enters the screen, leading zeros kept in shadow.
- Category: [Text & scroll](https://library.aimran.es/components/text-scroll)
- Built with: React + Motion
- Live editor: https://library.aimran.es/blocks/odometer-rolling-number
- Library: AIMRAN Library (https://library.aimran.es), free, no sign-up, by Aimran Oukham
## Where to use it
An animated number counter makes one figure feel earned: litres of water saved by an NGO, orders shipped by a small shop, members of a community, money raised in a crowdfunding. The mechanical rollers spin up when the section scrolls into view, and the faded leading zeros hint at how much room there is to grow.
Use it for one figure, maybe two, not a whole grid of stats. Round numbers read faster than exact ones. Tapping adds to the count and rolls it again, which is fun in a demo; on a serious report you may want to remove that.
## Code
### React (Motion)
```tsx
import { useEffect, useRef, useState } from "react";
import { AnimatePresence, motion, useInView, useReducedMotion } from "framer-motion";
import { Plus } from "lucide-react";
interface OdometerCounterProps {
value?: number;
label?: string;
color?: string;
}
const DIGITS = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
function Digit({ d, delay, faded, reduce }: { d: number; delay: number; faded: boolean; reduce: boolean }) {
return (
{DIGITS.map((n) => (
{n}
))}
);
}
export default function OdometerCounter({
value = 128450,
label = "litres of water saved this year",
color = "#ffb547",
}: OdometerCounterProps) {
const ref = useRef(null);
const seen = useInView(ref, { once: true, amount: 0.5 });
const reduce = useReducedMotion() ?? false;
const [n, setN] = useState(0);
const [bump, setBump] = useState<{ id: number; amount: number } | null>(null);
const timer = useRef>(undefined);
useEffect(() => {
if (seen) setN(Math.max(0, Math.round(value)));
}, [seen, value]);
useEffect(() => () => clearTimeout(timer.current), []);
const add = () => {
const amount = 100 + Math.floor(Math.random() * 2400);
setN((x) => x + amount);
setBump({ id: Date.now(), amount });
clearTimeout(timer.current);
timer.current = setTimeout(() => setBump(null), 1400);
};
const target = String(Math.max(0, Math.round(value)));
const padded = String(n).padStart(target.length, "0");
const lead = padded.search(/[1-9]/);
const cells: ({ kind: "digit"; d: number; faded: boolean } | { kind: "sep" })[] = [];
[...padded].forEach((ch, i) => {
const fromRight = padded.length - i;
cells.push({ kind: "digit", d: Number(ch), faded: lead === -1 ? fromRight > 1 : i < lead });
if (fromRight > 1 && (fromRight - 1) % 3 === 0) cells.push({ kind: "sep" });
});
let k = 0;
return (
);
}
```
## 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 “Odometer number” block (Text & scroll) from AIMRAN Library to my project.
## What it is
A huge figure whose digits roll into place with a spring when it enters the screen, leading zeros kept in shadow.
## Chosen settings
- Number: 128450 (from 1000 to 999999)
- Label: "litres of water saved this year"
- Accent color: #ffb547
## 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 React + TypeScript, with framer-motion for the animation and lucide-react for the icons. 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
import { useEffect, useRef, useState } from "react";
import { AnimatePresence, motion, useInView, useReducedMotion } from "framer-motion";
import { Plus } from "lucide-react";
interface OdometerCounterProps {
value?: number;
label?: string;
color?: string;
}
const DIGITS = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
function Digit({ d, delay, faded, reduce }: { d: number; delay: number; faded: boolean; reduce: boolean }) {
return (
{DIGITS.map((n) => (
{n}
))}
);
}
export default function OdometerCounter({
value = 128450,
label = "litres of water saved this year",
color = "#ffb547",
}: OdometerCounterProps) {
const ref = useRef(null);
const seen = useInView(ref, { once: true, amount: 0.5 });
const reduce = useReducedMotion() ?? false;
const [n, setN] = useState(0);
const [bump, setBump] = useState<{ id: number; amount: number } | null>(null);
const timer = useRef>(undefined);
useEffect(() => {
if (seen) setN(Math.max(0, Math.round(value)));
}, [seen, value]);
useEffect(() => () => clearTimeout(timer.current), []);
const add = () => {
const amount = 100 + Math.floor(Math.random() * 2400);
setN((x) => x + amount);
setBump({ id: Date.now(), amount });
clearTimeout(timer.current);
timer.current = setTimeout(() => setBump(null), 1400);
};
const target = String(Math.max(0, Math.round(value)));
const padded = String(n).padStart(target.length, "0");
const lead = padded.search(/[1-9]/);
const cells: ({ kind: "digit"; d: number; faded: boolean } | { kind: "sep" })[] = [];
[...padded].forEach((ch, i) => {
const fromRight = padded.length - i;
cells.push({ kind: "digit", d: Number(ch), faded: lead === -1 ? fromRight > 1 : i < lead });
if (fromRight > 1 && (fromRight - 1) % 3 === 0) cells.push({ kind: "sep" });
});
let k = 0;
return (