# Image Alt Text Checker | Accessibility & SEO Auditor (`andok/alt-text-auditor`) Actor

Bulk audit websites for missing image alt text. Improve image SEO rankings and ensure web accessibility compliance (ADA/WCAG) with automated scanning.

- **URL**: https://apify.com/andok/alt-text-auditor.md
- **Developed by:** [Andok](https://apify.com/andok) (community)
- **Categories:** SEO tools, Developer tools
- **Stats:** 3 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $0.47 / 1,000 page auditeds

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.
Since this Actor supports Apify Store discounts, the price gets lower the higher subscription plan you have.

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

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
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.
Actors are written with capital "A".

## 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.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## Image Alt Text Accessibility Auditor

Audit image alt text for WCAG accessibility compliance across any website. Missing or empty alt attributes are the most common accessibility violation on the web -- and they hurt both screen-reader users and your SEO rankings. Scan hundreds of pages in bulk and get an instant accessibility score with a detailed per-image breakdown of every issue.

### Features

- **Missing alt detection** — flags every `<img>` tag with no `alt` attribute at all
- **Empty alt detection** — catches images with `alt=""` that may need descriptive text
- **Accessibility score** — calculates a 0-100 score per page based on the ratio of properly tagged images
- **Lazy-load support** — checks both `src` and `data-src` attributes to catch lazy-loaded images
- **Full URL resolution** — resolves relative image paths to absolute URLs for easy reference
- **Bulk processing** — scan hundreds of URLs in a single run with configurable concurrency
- **Pay-per-event billing** — you only pay for each page audited, with automatic charge-limit enforcement

### Input

| Field | Type | Required | Default | Description |
|-------|------|----------|---------|-------------|
| `urls` | `array` | Yes | — | List of page URLs to audit for image alt text accessibility issues. |
| `timeoutSeconds` | `integer` | No | `15` | Maximum seconds to wait for each page response before timing out. |
| `concurrency` | `integer` | No | `10` | Number of pages to process in parallel. Increase for large batches, decrease if you hit rate limits. |

#### Input Example

```json
{
  "urls": [
    "https://crawlee.dev/",
    "https://apify.com/",
    "https://example.com/"
  ]
}
```

### Output

Each URL produces one dataset item with an accessibility score and a detailed image-by-image breakdown.

- `inputUrl` (`string`) — the URL you submitted
- `finalUrl` (`string`) — the URL after redirects
- `status` (`number`) — HTTP status code
- `totalImages` (`number`) — total number of `<img>` tags found on the page
- `missingAlt` (`number`) — count of images with no `alt` attribute
- `emptyAlt` (`number`) — count of images with empty `alt=""`
- `accessibilityScore` (`number`) — 0-100 score (percentage of images with valid alt text)
- `images` (`array`) — per-image details:
  - `src` (`string`) — resolved absolute URL of the image
  - `alt` (`string | null`) — the alt text value, or `null` if missing
  - `issue` (`string`) — `"missing"`, `"empty"`, or `"ok"`
- `error` (`string | null`) — error message if the URL could not be fetched

#### Output Example

```json
{
  "inputUrl": "https://example.com/",
  "finalUrl": "https://example.com/",
  "status": 200,
  "totalImages": 12,
  "missingAlt": 3,
  "emptyAlt": 1,
  "accessibilityScore": 67,
  "images": [
    {
      "src": "https://example.com/images/hero.jpg",
      "alt": "Product dashboard overview",
      "issue": "ok"
    },
    {
      "src": "https://example.com/images/banner.png",
      "alt": null,
      "issue": "missing"
    },
    {
      "src": "https://example.com/images/logo.svg",
      "alt": "",
      "issue": "empty"
    }
  ]
}
```

### Pricing

| Event | Cost |
|-------|------|
| Page Audited | Pay-per-event (see actor pricing page) |

The actor stops automatically when the per-run charge limit is reached, so you never overspend.

### Use Cases

- **WCAG compliance** — audit your site for alt text violations before an accessibility review or legal deadline
- **SEO improvement** — search engines use alt text for image indexing; fix gaps to improve image search rankings
- **Agency deliverables** — generate accessibility reports for clients with per-page scores and specific remediation items
- **Content QA** — catch missing alt text in CMS-managed content before it reaches production
- **Accessibility monitoring** — schedule recurring runs to track your accessibility score over time

### Related Actors

| Actor | What it adds |
|-------|-------------|
| [Broken Links Checker](https://apify.com/andok/broken-links-checker) | Finds broken links and images — combine with alt text auditing for a complete page quality check |
| [OpenGraph & Twitter Card Inspector](https://apify.com/andok/opengraph-inspector) | Validates social preview tags — pair with accessibility auditing for full content QA |
| [Website Tech Stack Analyzer](https://apify.com/andok/tech-stack-analyzer) | Detects the CMS behind each page — understand which platform is generating the accessibility issues |

# Actor input Schema

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

List of page URLs to audit for image alt text accessibility. Each page is scanned for <img> tags with missing or empty alt attributes.

## `timeoutSeconds` (type: `integer`):

Maximum seconds to wait for each page response. Increase for slow or geographically distant sites.

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

Number of pages to process in parallel. Higher values speed up large batches but may trigger rate limits on some hosts.

## Actor input object example

```json
{
  "urls": [
    "https://crawlee.dev/"
  ],
  "timeoutSeconds": 15,
  "concurrency": 10
}
```

# Actor output Schema

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

No description

## `resultsCsv` (type: `string`):

No description

## `run` (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://crawlee.dev/"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("andok/alt-text-auditor").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://crawlee.dev/"] }

# Run the Actor and wait for it to finish
run = client.actor("andok/alt-text-auditor").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://crawlee.dev/"
  ]
}' |
apify call andok/alt-text-auditor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,andok/alt-text-auditor"
        }
    }
}

```

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/cJfgwPv16OQuYti0a/builds/W9DceeIg53GdthXuB/openapi.json