Six reasons to stop using PDFs on your website

Adobe created the Portable Document Format (PDF) in 1993, initially designed to enable consistent document formatting across devices. Over 30 years later, we're still using PDFs to share information, but for accessibility's sake, they need to go.

While PDFs are popular for sharing documents online, especially in government organisations and education, they have significant accessibility drawbacks.

PDFs create barriers for disabled users, with research suggesting that 67% of PDFs encountered online were inaccessible. This is because they are either partially or entirely unreadable for assistive technology.

PDFs are well and truly past their use by date, so here are six reasons you should stop using PDFs on your website:

1. PDFs can be hard to access
2. PDFs aren't designed for assistive technology
3. PDFs aren't responsive
4. PDFs aren't very well maintained
5. PDFs aren't energy efficient
6. PDFs aren't great for SEO

In PDF's defence, they weren't designed to be digital-first accessible content. They were initially designed to replicate printed documents visually. Because of this, many inaccessible documents are floating around online.

With over 2.5 trillion PDFs available worldwide, millions of inaccessible documents are being used to share information. This is a huge problem, as users reliant on assistive technology cannot access basic information, such as healthcare records and online bank statements.

To make a PDF accessible, users must:

• Set up proper document structure and include document properties (also known as PDF metadata)
• Add alternative text descriptions for images and non text elements
• Make text selectable
• Follow the steps in our accessible PDF checklist

PDFs aren't born accessible. Accessibility features must be manually added, making the creation of accessible PDFs time-consuming. Without correct training, users responsible for making PDFs will create inaccessible documents.

Inaccessible PDFs predominantly affect users who:

• Rely on screen readers
• Navigate via keyboard alone
• Require text magnification or high-contrast settings
• Experience cognitive or learning disabilities

Even with accessibility improvements, PDFs frequently cause problems for screen reader users. Common issues include missing heading structures, insufficient alt text for images, inaccessible tables and poor support for form controls and interactivity.

Generally speaking, PDFs aren't responsive because they are designed to preserve their original formatting. This is a problem for assistive technology because PDFs cannot dynamically reorganise or resize content, fonts, or images without manual intervention.

HTML web pages, in contrast, are responsive and offer a better user experience (UX) for everyone. Responsive web pages significantly improve accessibility by ensuring content remains clear, navigable, and usable regardless of device or user context.

Most people will know that PDFs are hard work to maintain. Making changes to a PDF is even more challenging if you don't have access to the source document.

There are many reasons why PDF maintenance gets neglected, for example:

• Without the source document, you'll require specialist software to make changes.
• Maintaining PDFs is a complex and manual process.
• At scale, maintaining PDFs is a costly and resource intensive task.
• Making PDFs accessible retrospectively is a manual, time consuming process.

Even minor edits or updates—such as adding a paragraph, updating a table, or replacing images—can disrupt PDF accessibility, requiring accessibility checks and adjustments to start all over again.

In contrast, HTML or structured web-based content offers considerable advantages. Starting with the obvious, HTML web pages are easy to maintain. In addition, HTML has built-in accessibility benefits, such as compatibility with assistive technology.

HTML is a cost-effective alternative to PDFs, provides a better UX to all and is accessible.

Did you know that your PDFs are resource hogs? Well, in comparison to HTML web pages, they are. Large PDFs require more storage space, increased bandwidth to download, and higher data transmission energy use than HTML web pages.

Research from the Government Communication Service found that when presenting the same information as HTML and PDF, the HTML page was "significantly smaller" and emitted less CO2e every time someone viewed it.

So, in addition to inclusivity, think about data poverty, too. Creating light, mobile-friendly web pages is critical for users in remote locations with unreliable internet connections. Reducing the size of your web pages can greatly improve page load speed and UX.

Search engine optimisation and accessibility go hand in hand. If humans can’t read your document, search engine crawlers can’t. Therefore, including key information in PDFs can harm your organic SEO potential.

It's no surprise that PDFs are not the best choice for SEO, and here’s why:

• Crawling challenges: PDFs are more difficult for search engines to crawl accurately. Even when indexed, they tend to rank lower in search results than HTML content.
• Page speed and performance: Google considers page speed and performance as key factors for SEO rankings. Since PDFs are typically larger files, they can negatively affect site performance, which in turn impacts SEO rankings.
• Limited navigation: PDFs usually do not allow effective internal navigation, significantly reducing internal linking opportunities.
• User experience issues: Due to a generally poor UX, PDFs often lead to higher bounce rates and shorter dwell times, both of which can adversely affect SEO rankings.
• Search engine preference: Search engines prioritise content that is relevant, accessible, structured clearly, and optimised for UX and device compatibility, such as HTML. Unfortunately, PDFs don't fit that description.

Search engines prioritise HTML web pages primarily, followed by structured and optimised content. Formats that typically rank lower in SERPs are PDFs due to their limited crawlability and optimisation.

We've mentioned HTML quite a few times in this blog, and for good reason. HTML is a better alternative format to PDFs for sharing information online.

In case there was any doubt, the benefits of using HTML include:

• HTML has acessibility features built-in with responsive web pages
• HTML works with assistive technology
• It's easier and cheaper to maintain and access
• HTML is more energy efficient
• HTML provides a better user experience

In addition, the UK Government Digital Service (GDS) explicitly discourages PDFs, promoting HTML formats through their "GOV.UK Content Design Guidelines," citing increased accessibility, usability, and engagement.

While HTML is generally superior for accessibility, responsiveness, and SEO - PDFs still have a place in specific contexts, for example, legal authentication and security. Organisations should carefully assess user needs and always supplement PDFs with accessible HTML alternatives wherever possible.

To find inaccessible PDFs on your website, you can use automated accessibility testing tools or manually audit.

Tools such as Insytful scan for missing metadata, inaccessible reading orders, a lack of alternative text, and other PDF-specific barriers. Insytful's PDF and document inventory lists all the PDFs listed on your site plus other useful metrics like their size and metadata.

Despite their drawbacks in accessibility and responsiveness, there are still some scenarios in which using PDFs can be more practical than using HTML.

Here are some cases where PDFs might be preferable:

• Documents requiring signatures - PDFs support digital signatures, providing legal authenticity for contracts, invoices, certificates, or official paperwork.
• Print-ready documents - PDFs ensure precise control over formatting, layouts, and fonts, making them ideal for printed publications that need exact replication.
• Offline access and distribution - PDFs provide stable offline access which is suitable for scenarios with limited or no internet access.

• Ensure PDFs are tagged and fully accessible (with proper semantic tagging, alt-text, and logical reading order).
• Provide an HTML alternative alongside the PDF for improved accessibility and SEO.
• Indicate when PDFs are used, along with file size, so that users can anticipate and manage downloads effectively.