Heading and Alt Text Checker
Check heading hierarchy and image alt text on one page, no sign-up required.
Tool
This tool fetches the address you enter from our server once, extracts every heading from h1 to h6 in document order and shows them as an indented outline; it lists every img tag with its alt text, width and height attributes, loading="lazy" marker, whether it sits inside a picture element and whether it has a srcset. At the top you see the number of headings, h1s, images, images without an alt attribute and words in the visible text; below that come the findings, each with what to do. The image table can be copied as CSV.
Heading hierarchy matters to three readers: a visitor scanning the page tells sections apart by their headings, a screen reader user jumps through the page from the heading list, and a search engine reads the layout of the content from the same structure. The tool flags a missing h1, more than one h1, skipped levels (h4 straight after h2, for example), empty and duplicate headings, headings longer than 70 characters and a first heading that is not an h1, each separately. A single h1 is not a requirement but the common and safe choice; the HTML standard allows several, yet one main heading is clearer for screen readers and search engines. Alt text tells a visitor who cannot see the image what it conveys and helps image search understand the content; the tool marks images with no alt attribute at all as missing, empty alt as decorative, and alt text longer than 125 characters or equal to the file name as needing review.
The tool reads only the HTML your server returns; headings and images added in the browser by JavaScript, CSS background images and script-loaded galleries are invisible to it. It does not check whether the images actually load, their file size or compression, and only a person can judge whether alt text truly matches the image. The result is kept in server memory for 10 minutes for the same address, then cleared; nothing beyond the address you enter is read.
FAQ
Is using more than one h1 a mistake?
No, the HTML standard allows several h1s and Google has said this alone is not a ranking problem. A single h1 still makes the main topic clear for screen reader users and search engines, which is why one h1 is the common and safe choice.
Should I write alt text for decorative images?
Give decorative images an empty alt (alt="") so screen readers skip them. Do not remove the attribute altogether, as some screen readers then read the file name. For informative images, write a short sentence saying what the image shows.
Can the tool see headings and images built with JavaScript?
No, only the first HTML the server returns is read. On pages that build their content in the browser with scripts, the outline and image list may be incomplete; compare the result with your browser's "view page source" output.
Why does it ask for width and height attributes?
The browser uses the two values to work out the aspect ratio and reserve space before the image loads, so content does not jump down while loading. You can still size the image flexibly with CSS; the attributes only declare the ratio.
