DEV3 Heading and Alt Text Checker — Source Code (Next.js + MongoDB)

Source code of the DEV3 Heading and Alt Text Checker, a page checker that extracts the H1 to H6 outline, images with missing or weak alt text and links with empty or vague text, with CSV export.

Download: buy a licence and the ZIP is waiting in Account → Downloads. Try it live: https://dev3.tech/tools/heading-alt-text-checker shows the finished tool running.

What is in the download

• Route handlers and pages for the Next.js App Router
• The service layer, Mongoose models and the UI components, in a dev3-tools/ folder that cannot clash with your own files
• README.md (install, environment, customise), .env.example and an MIT LICENSE

What the code does

• Outline issues: no H1, several H1s, skipped levels, empty headings
• Alt text quality rules including placeholders and file names
• Link text rules for empty, generic and raw URL text; image links use alt text
• Built on the dependency-free html-scan tag walker

Tech stack

Next.js 15 (App Router), React 19, TypeScript, Mongoose on MongoDB, Tailwind CSS 4.

Install and customise

The How to install and How to use tabs list the steps. In short: copy the module into a Next.js app, install the listed packages, add the MongoDB connection string and run it.

Good to know

• This is server code: you need a MongoDB database and your own hosting.
• No JavaScript execution; lists the first 1,000 images and 1,500 links.