# Check if a string contains only letters and numbers

Test for one or more ASCII letters or digits.

Canonical: https://1loc.dev/validator/check-if-a-string-contains-only-letters-and-numbers/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function isAlphanumeric(text) { return /^[0-9A-Z]+$/i.test(text); }
```

## Input

```json
"Order8812"
```

## Expected output

```json
true
```

## Edge case

Input:
```json
"Order 8812"
```
Output:
```json
false
```

## Limits

- ASCII only: accented letters and spaces fail. The empty string fails too.

The lab validates types and size before calling this function. Add equivalent validation at your own trust boundary.

## Source and license

Original: https://github.com/phuocng/1loc/blob/14b481cf60dff1620ab1bb99a43b1f68068cdd9b/contents/check-if-a-string-contains-only-letters-and-numbers.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: See original repository history
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Curated implementation; explicit input contract, edge case and limits. Original MDX retained as inert source evidence.