HTML ID Extractor

The HTML ID Extractor scans HTML source code and lists every id attribute it contains, showing how many times each id value appears and clearly flagging any that are used more than once. Because an id is supposed to be unique within a document, duplicates are a genuine bug, and this tool surfaces them at a glance instead of leaving you to hunt through the markup.

It is built for developers, QA engineers, and accessibility auditors who rely on ids for anchor links, label associations, JavaScript selectors, and ARIA relationships. When two elements share an id, in-page anchors jump to the wrong place, label clicks focus the wrong field, getElementById returns only the first match, and assistive technology can behave unpredictably. Catching those collisions early saves hours of confusing debugging.

All processing happens locally in your browser using JavaScript, with no upload and no server involved. Paste the page source or upload an HTML file, and the table of ids with their counts and status appears instantly. Because nothing leaves your device, you can safely inspect private templates, generated markup, and confidential pages.

Features

• Extracts every id attribute value from the markup, preserving the order in which each first appears.
• Counts how many times each id value is used so repeated ids are impossible to miss.
• Flags each id as unique or duplicate, making invalid repeated ids immediately obvious in the table.
• Handles single quoted, double quoted, and unquoted id attribute syntaxes for thorough coverage.
• Ignores commented-out markup so ids inside HTML comments never appear as false positives.
• Reports the number of unique ids and how many ids are duplicated as quick summary statistics.
• Exports the table to CSV or XLSX, or copies it to your clipboard for a bug report or audit.

How to use HTML ID Extractor

1. Paste your HTML source into the input box, or upload an .html, .htm, or .txt file from your device.
2. Read the generated table listing each id, its usage count, and whether it is unique or duplicated.
3. Scan the status column for any id marked as duplicate, since those violate HTML uniqueness rules.
4. Cross-reference duplicated ids in your source and rename or remove the extra occurrences.
5. Check the stats to see the total number of unique ids and how many are duplicated overall.
6. Export the table to CSV or XLSX, or copy it to attach to a bug ticket or code review.

Benefits

• Developers catch duplicate ids that silently break anchor links, label clicks, and script selectors.
• QA engineers verify id uniqueness across generated or templated pages before they reach production.
• Accessibility auditors confirm that ARIA relationships reference unique, valid ids as required.
• Teams building forms ensure each label points at a single, correctly identified input field.
• Framework users spot repeated ids introduced by looping over components without unique keys.
• Anyone reviewing unfamiliar markup gets an instant map of the ids a page exposes for targeting.

Duplicate ids are among the most deceptive HTML bugs because the page often looks fine while behaving wrongly. An in-page link to a repeated id scrolls to only the first match, a label wired to a duplicated id focuses the wrong control, and document.getElementById quietly returns the first element while your code assumes another. Listing every id with its count turns these invisible collisions into a concrete list you can fix with confidence.

The tool is especially useful when markup is generated in loops or assembled from reusable components, which is exactly where duplicate ids tend to sneak in. If a component hard-codes an id and you render it several times, every instance collides. The status column makes that pattern obvious, so you can switch to unique, index-based, or key-derived ids before the duplication causes anchor, form, or scripting failures downstream.

Because the extractor parses HTML with regular expressions in your browser, it reads the ids exactly as written in the source and never uploads anything, working even in server-side rendering contexts. It preserves first-seen order so the table mirrors your document top to bottom. It reports duplicates within the single document you paste, so combine snippets into one input when you want to check for collisions across an assembled page.