# Hreflang Validator & Checker for International SEO (`psx/hreflang-validator`) Actor

Validate hreflang annotations (HTML link tags and HTTP headers) for multilingual sites: invalid codes, missing self-reference, missing x-default, canonical conflicts and missing return links on alternates. Plain HTTP.

- **URL**: https://apify.com/psx/hreflang-validator.md
- **Developed by:** [psx](https://apify.com/psx) (community)
- **Categories:** SEO tools, Developer tools
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

Pay per event

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Hreflang Validator for International SEO

Validate the hreflang setup of multilingual and multi-region sites, including the part most tools skip: do the alternates actually link back? Plain HTTP, no browser, no personal data.

### What it checks

- Annotations from HTML `<link rel="alternate" hreflang>` and the HTTP `Link` header.
- Codes: `invalid-code` (e.g. `en-UK`, `jp`, `en_US`, numeric regions like `es-419`, wrong case of `x-default`).
- Set integrity: `missing-self-reference`, `missing-x-default`, `conflicting-duplicate`, `duplicate`, `single-annotation`, `non-absolute-url`, `mixed-protocols`, `canonical-mismatch`.
- Return links (optional, default on): fetches each alternate (up to `maxAlternates`) and reports `missing-return-link`, `alternate-http-error`, `alternate-unreachable`, `alternate-redirects`, `alternate-canonical-mismatch`.
- Sitemap-based hreflang (`xhtml:link`) is not covered in this version.

### Input

| Field | Default | Description |
|---|---|---|
| `urls` | required | Pages to validate (up to 2,000), one per site or template. |
| `checkReturnLinks` | `true` | Fetch alternates to verify reciprocity. |
| `maxAlternates` | `25` | Max alternates fetched per page (max 60). |
| `respectRobots` | `true` | Skip disallowed pages (not charged). |
| `delayMs` | `400` | Delay per host. |
| `concurrency` | `3` | Pages in parallel. |

### Output

```json
{ "url": "https://example.com/en/", "status": 200, "hreflangCount": 4, "alternatesChecked": 3, "score": 88,
  "entries": [{ "hreflang": "de", "href": "https://example.com/de/", "source": "html" }],
  "issues": [{ "severity": "high", "id": "missing-return-link", "message": "Alternate does not link back to this page (return links are required).", "hreflang": "fr", "href": "https://example.com/fr/" }] }
```

Severity: `high` -12, `medium` -5, `low` -1 points from 100.

### Safety and etiquette

Private/internal addresses blocked (SSRF guard on every redirect and at DNS level). robots.txt respected by default, max 2 parallel requests per host with a delay. The alternates fetched are the pages the site itself declares.

### Pricing (pay per event)

`apify-actor-start` $0.005 per run (per GB), `site-checked` $0.005 per input URL fetched successfully (return-link checks of up to `maxAlternates` pages included; errors and robots-skipped pages not charged).

### Develop

`npm install && npm test`; local run via `storage/key_value_stores/default/INPUT.json` + `npm start`; deploy `apify push` (private by default).

# Actor input Schema

## `urls` (type: `array`):

Pages whose hreflang set should be validated (up to 2,000). Typically a home page or key template per site. Bare domains accepted.

## `checkReturnLinks` (type: `boolean`):

Fetch each alternate (up to the limit below) to verify it links back, returns 200 and does not redirect. Included in the per-site price.

## `maxAlternates` (type: `integer`):

Upper bound of alternate pages fetched per input URL.

## `respectRobots` (type: `boolean`):

Skip pages disallowed by robots.txt (skipped pages are not charged).

## `delayMs` (type: `integer`):

Minimum delay between requests to the same host.

## `concurrency` (type: `integer`):

Input URLs processed in parallel (at most 2 requests per host).

## Actor input object example

```json
{
  "urls": [
    "https://www.apple.com/"
  ],
  "checkReturnLinks": true,
  "maxAlternates": 25,
  "respectRobots": true,
  "delayMs": 400,
  "concurrency": 3
}
```

# Actor output Schema

## `results` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "urls": [
        "https://www.apple.com/"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("psx/hreflang-validator").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "urls": ["https://www.apple.com/"] }

# Run the Actor and wait for it to finish
run = client.actor("psx/hreflang-validator").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "urls": [
    "https://www.apple.com/"
  ]
}' |
apify call psx/hreflang-validator --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,psx/hreflang-validator"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/ZvJHPXJWQbMgtEEPL/builds/Goed32NXpo0oNyVie/openapi.json