What Is data-start data-end and Is It Exposing Your AI Content?

Have you ever used an AI chatbot like OpenAI’s ChatGPT to generate content, copied the text, and noticed strange HTML attributes like data-start="161" or data-end="219" when pasting it into your website editor? For example, if you’re using a platform like WordPress and switch to the HTML view, you might come across something like <h2 data-start="6387" data-end="6404">. These odd-looking pieces of code often show up around headings, paragraphs, and bold text after pasting from an AI tool or text editor.

This issue becomes especially noticeable when writing blog posts, articles, essays, or even exams using AI-generated content. When you copy and paste the content directly into a visual editor or block editor, the HTML code often includes these extra data-start and data-end attributes on standard HTML tags like <h1>, <h2>, <p>, <strong>, and more. While these attributes don’t affect how the content looks to your readers, they can create a messy back-end that’s frustrating to clean up. In some cases, even the AI that generated the content may struggle to remove them correctly.

Because of this, some people believe that finding data-start and data-end in the code is a telltale sign that AI was used to create the content. And while that’s sometimes true, it’s not always the case. The presence of these attributes may simply mean that AI was used to assist with formatting, structure, or even spell-checking. It doesn’t necessarily mean the entire piece was generated by artificial intelligence. But it does raise an important question for content creators, developers, and webmasters: are data-start and data-end attributes harmful to your website’s SEO?

What is data-start data-end?

data-start and data-end are custom HTML attributes, commonly referred to as data attributes, that are automatically added to elements when copying and pasting content from certain applications; particularly AI chatbots like ChatGPT or visual editors like Notion. These attributes are not part of standard HTML but are instead used by software to track the position of elements within the original source for editing, rendering, or document management purposes.

When you copy content directly from an AI chatbot, especially one that uses a rich-text interface, the output may include extra metadata wrapped inside HTML tags. The data-start attribute typically marks the beginning character index of a segment of text in the source editor, while data-end marks the end character index. These are mostly used internally and were never meant to be published online. However, when the text is pasted into platforms like WordPress, Blogger, Wix, or even raw HTML files, these attributes are copied along with the text and end up in your page’s code.

For example, you may see something like this in your HTML:

<h2 class="" data-start="6387" data-end="6404">Final Thoughts</h2>
<p class="" data-start="6406" data-end="6667">Dogs and cats may be very different, but they each bring unique joy and companionship into our lives. Whether you love the wag of a dog’s tail or the gentle purr of a cat curled up beside you, there’s no denying the special bond humans share with these animals.</p>
<p class="" data-start="6669" data-end="6925">Ultimately, it’s not about which pet is better—it’s about the love, laughter, and comfort they bring to our homes. Whether you’re a cat person, a dog person, or somewhere in between, our furry friends enrich our lives in ways that words can barely capture.</p>

In this example, the <h2> and <p> tags include extra attributes that do not serve any functional purpose for web browsers or search engines. They were likely included during the copy-and-paste process from an AI chatbot or a WYSIWYG editor that uses these tags to track content changes or formatting positions.

While these attributes don’t display on the front end of your site and usually don’t affect how the content looks to readers, they do bloat your HTML code and may be seen as unclean or unnecessary by developers and SEO professionals. They also may raise flags to editors or reviewers who recognize that the content was likely assisted or created using an AI tool.

Most importantly, data-start and data-end are not recognized or used by search engines like Google, Bing, or others for indexing, ranking, or displaying content. They are purely internal metadata and can safely be removed without affecting your page’s appearance or function. However, their presence may reveal the content’s source or editing history, especially if someone is reviewing your HTML code for authenticity or originality which can easily be done by checking the page’s source code or by using a website scraper like the one on our website.

To summarize: data-start and data-end are invisible markers used by editing tools and AI platforms to track text positions and the numbers indicate the character positions of the text within the original source or document from which the content was copied. While harmless in most cases, they can clutter your HTML and potentially signal that AI tools were involved in the content creation process. It’s good practice to remove them before publishing to keep your code clean and professional.

Is data-start data-end harmful?

No, data-start and data-end attributes are not harmful. These attributes are completely safe, do not indicate malware, a hack, or a virus, and currently have no negative impact on SEO. They are simply leftover metadata that may be added when copying content from AI tools like ChatGPT or rich-text editors. While they might look unusual in your HTML, they do not affect how your website functions, appears to visitors, or ranks in search engines.

From an SEO standpoint, data-start and data-end do not harm your search rankings. Google and other search engines typically ignore unknown data-* attributes unless they’re part of structured data like schema markup — which these are not. Google also doesn’t penalize AI-assisted content, as long as it’s original, helpful, and not spammy. Including these attributes won’t cause your content to be flagged or demoted in search results.

That said, while the attributes are technically safe, it’s still good practice to remove them before publishing. Clean HTML makes your site easier to manage, avoids confusion when editing code, and presents a more professional back-end — especially in team environments or when clients and reviewers may inspect the source code. It also prevents the appearance of unnecessary or suspicious tags that could raise questions.

If you come across these attributes and don’t recognize them, it’s understandable to worry about a possible infection or breach. Fortunately, data-start and data-end are not signs of malware or hacking. They’re simply artifacts from copying formatted content between applications. Still, if you want to be sure your system or website is safe, it’s always a smart idea to run a malware scan.

To check for threats and ensure your device or site hasn’t been affected by anything malicious, we recommend scanning with Malwarebytes. It’s fast, reliable, and can detect hidden malware, unwanted programs, and browser hijackers that may not show obvious symptoms.

In summary, data-start and data-end are not dangerous and pose no risk to your site’s SEO or security. They can be safely ignored, but removing them helps keep your HTML clean and your workflow more efficient. And if you ever encounter code you don’t recognize, running a quick malware scan can offer peace of mind.

How to remove data-start data-end

Removing data-start and data-end from your HTML is easy once you know how, but depending on the amount of content, it can become time-consuming. These extra attributes are often added automatically when copying and pasting content from AI tools or online editors, but they serve no purpose in your published content and should be removed to keep your HTML clean.

Here are the most effective ways to remove data-start and data-end attributes from your content:

• Manual Removal: If you’re editing a short post or a small piece of content, you can simply switch to your HTML or text editor and manually delete any instance of data-start="..." and data-end="...". Use the “Find” feature (Ctrl+F or Cmd+F) in your editor to quickly locate these tags.
• Search and Replace (Text Editor or Code Editor): If you’re working with a lot of content or files, use a code editor like VS Code, Sublime Text, or Notepad++. You can run a bulk find and replace using regular expressions. For example, use a search pattern like data-start="[^"]*" and replace it with nothing to remove all data-start attributes. Repeat with data-end="[^"]*".
• WordPress Block Editor Cleanup: If you’re using WordPress, switch to the “Code Editor” (top-right options menu in the block editor) and remove these attributes directly from the source code. If you’re working with reusable blocks or templates, make sure they’re clean too.
• Online HTML Cleaners: There are free online tools like HTML-Cleaner.com that let you paste your HTML code and strip out unwanted attributes with one click. These tools are great for quick cleanups without needing technical knowledge.
• Ask AI to Remove it: You can paste your HTML content back into an AI chatbot like ChatGPT and ask it to “remove all data-start and data-end attributes.” However, AI is not always perfect with large blocks of HTML and may alter the formatting or structure, so review the result before publishing.
• Automated Scripts (for Developers): If you’re working with dynamic or templated content, a custom script using a language like Python or JavaScript can automatically parse and remove these attributes from multiple files at once. This is useful for larger websites or batch-processing content.

Although removing data-start and data-end is straightforward, it can become tedious if there are hundreds of instances throughout a document. AI may not always retain perfect formatting during cleanup, and manual deletion can take time. That’s why many prefer using regular expressions or automated tools to handle bulk content more efficiently.

To avoid the hassle altogether, check out the next section for tips on preventing these attributes from appearing in your content in the first place.

How to avoid data-start data-end

If you want to avoid dealing with data-start and data-end attributes entirely, the best approach is to prevent them from being added in the first place. These attributes typically appear when you copy and paste directly from an AI chatbot interface or rich-text editor that supports styled formatting. Fortunately, there are a few simple methods to ensure your output stays clean and free of these unwanted tags.

• Ask for Code Block Output: When using ChatGPT or another AI chatbot, ask it to provide the content in a code block (fenced with triple backticks “` or shown as preformatted text). This ensures the output is in plain text format and does not include hidden formatting or metadata.
• Use “Plain Text” Mode When Pasting: Before pasting content into your website, switch your editor to plain text mode or code view. In WordPress, this is called the “Code Editor.” Pasting into a visual editor can sometimes carry over formatting data.
• Paste into a Plain Text Editor First: A simple trick is to paste the content into a plain text editor like Notepad (Windows) or TextEdit (Mac in plain text mode) first. Then copy and paste it into your website editor. This strips all metadata and formatting.
• Use Clean Export Tools (Where Available): Some platforms offer a “copy as plain text” or “export without formatting” option. If available, use that to generate clean output.
• Check the HTML Before Publishing: Before hitting publish, always review the source or HTML code of your content to ensure there are no unnecessary attributes or tags.

By taking a few extra seconds to request plain text or paste into a text-only editor, you can completely avoid the hassle of dealing with data-start and data-end attributes later on. This keeps your HTML clean, your site lightweight, and your workflow efficient—especially if you regularly use AI to assist with content creation.