Image Alt Text Checker

Check images on web pages for missing, empty, or poor alt text for SEO and accessibility compliance.

What does Image Alt Text Checker do?

This actor analyzes image alt attributes on web pages. It detects missing alt text, identifies decorative images (empty alt=""), flags file name alts, and warns about overly long descriptions (>125 chars). Each page gets a score based on alt text coverage and quality.

Image alt text serves two critical purposes: it describes images to visually impaired users who rely on screen readers, and it helps search engines understand image content for image search rankings. This actor audits every image on your pages and quantifies alt text quality with a single score.

The output provides a complete breakdown of image counts by category -- images with alt text, images without alt text, decorative images, images with overly long alt text, and images using file names as alt text. Each page receives a quality score from 0 to 100, making it easy to identify and prioritize the specific issues to fix.

Use cases

• Accessibility auditor -- verify that all images meet WCAG 2.1 requirements for text alternatives across an entire website
• SEO specialist -- find pages with missing alt text that represents lost image search ranking opportunities
• Content manager -- ensure editorial standards are met before publishing pages with images
• Compliance officer -- generate accessibility compliance reports for stakeholders or regulatory requirements
• Migration engineer -- verify that image alt text survives CMS migrations, platform changes, or template updates
• E-commerce product manager -- ensure all product images have descriptive alt text that includes product names and attributes for image search visibility

Why use Image Alt Text Checker?

• Multiple issue types detected -- missing alt, empty alt, file name alts, and overly long alt text (>125 chars)
• Decorative image awareness -- correctly identifies intentionally empty alt="" for decorative images
• Page-level scoring -- each page gets a quality score so you can prioritize fixes
• Batch processing -- check hundreds of pages in a single run
• Structured JSON output -- results include image counts, issue categories, and scores ready for reporting
• Pay-per-event pricing -- costs just $0.001 per page checked
• Fast and lightweight -- uses direct HTTP requests without a browser for quick results at minimal cost

Input parameters

Parameter	Type	Required	Default	Description
urls	array	Yes	--	List of web page URLs to check image alt text on. Each page is analyzed independently.

Input example

{
    "urls": [
        "https://www.google.com",
        "https://en.wikipedia.org/wiki/Web_scraping",
        "https://www.bbc.com"
    ]
}

Output example

{
    "url": "https://www.bbc.com",
    "title": "BBC - Home",
    "totalImages": 45,
    "imagesWithAlt": 38,
    "imagesWithoutAlt": 3,
    "decorativeImages": 4,
    "altTooLong": 0,
    "fileNameAlts": 0,
    "score": 96,
    "issues": ["3 image(s) missing alt attribute"],
    "error": null,
    "checkedAt": "2026-03-01T12:00:00.000Z"
}

How much does it cost?

Event	Price	Description
Start	$0.035	One-time per run
URL checked	$0.001	Per page checked

Example costs:

• 10 URLs: $0.035 + (10 x $0.001) = $0.045
• 100 URLs: $0.035 + (100 x $0.001) = $0.135
• 1,000 URLs: $0.035 + (1,000 x $0.001) = $1.035

Using the Apify API

You can call Image Alt Text Checker programmatically from your own applications using the Apify API. The following examples show how to start a run, wait for it to finish, and retrieve the results.

Node.js

import { ApifyClient } from 'apify-client';

const client = new ApifyClient({ token: 'YOUR_TOKEN' });

const run = await client.actor('automation-lab/image-alt-checker').call({
    urls: ['https://www.bbc.com'],
});

const { items } = await client.dataset(run.defaultDatasetId).listItems();
console.log(items);

Python

from apify_client import ApifyClient

client = ApifyClient('YOUR_TOKEN')

run = client.actor('automation-lab/image-alt-checker').call(run_input={
    'urls': ['https://www.bbc.com'],
})

items = client.dataset(run['defaultDatasetId']).list_items().items
print(items)

Integrations

Image Alt Text Checker works with all major automation and integration platforms available on Apify. Connect it to Make (formerly Integromat) or Zapier to trigger workflows when alt text issues are found on newly published pages. Export results to Google Sheets for accessibility audit tracking and team review. Send Slack alerts when pages have low alt text scores. Use webhooks to get notified as soon as a run completes, or integrate with n8n for custom automation pipelines. Schedule recurring runs on Apify to continuously monitor alt text quality across your site. All results are stored in Apify datasets and can be downloaded in JSON, CSV, or Excel format for further analysis and reporting.

Tips and best practices

• Focus on content images first -- images in the main content area have the most SEO and accessibility impact; decorative images can use empty alt=""
• Keep alt text under 125 characters -- screen readers may truncate longer descriptions, and search engines prefer concise alt text
• Avoid file name alts -- alt text like "IMG_2048.jpg" or "hero-banner.png" provides no value to users or search engines
• Run after content publishes -- new articles and product pages often have missing alt text; schedule checks after publishing workflows
• Combine with heading and title checks -- a complete accessibility audit should cover alt text, heading structure, and page titles together
• Do not start alt text with "image of" or "photo of" -- screen readers already announce that the element is an image, so these prefixes are redundant

FAQ

What is the difference between missing alt and empty alt? Missing alt means the alt attribute is not present on the <img> tag at all, which is an accessibility violation. Empty alt (alt="") is intentional and marks an image as decorative, telling screen readers to skip it.

What score should I aim for? A score of 100 means all images have appropriate alt text. Aim for 90+ on content-heavy pages. Pages with many decorative images (icons, spacers) may naturally have lower scores if those images correctly use empty alt attributes.

Does the actor check alt text quality? The actor checks for presence, length, and common problems like file name alts. It does not evaluate whether the alt text accurately describes the image content, as that requires visual analysis.

Why is alt text important for SEO? Search engines cannot see images the way humans do. Alt text is the primary way Google understands what an image depicts, which is essential for ranking in Google Image Search. Pages with descriptive alt text also tend to perform better in regular search results.

Are CSS background images checked? No. The actor only checks <img> tags in the HTML. CSS background images do not support alt attributes and are not part of the document's content structure. If important content is displayed as a CSS background image, consider converting it to an <img> tag.

How many URLs can I check in one run? There is no hard limit. You can check hundreds or thousands of pages in a single run. The actor processes each URL independently and concurrently for efficient results.

Does the actor check images loaded via JavaScript? The actor analyzes the initial HTML response. Images that are lazy-loaded or injected by JavaScript after page render may not be included in the analysis. Most content images in modern CMS platforms are present in the initial HTML with lazy-loading attributes, so this is rarely an issue in practice.