California Extreme Weather: Storms, Floods and Heatwave Risks

This blog post explains why a URL might return an image-only or otherwise inaccessible page instead of readable text. It provides practical, expert guidance for researchers, web managers, and content creators on how to diagnose and fix the problem.

Drawing on three decades of experience in scientific publishing and web accessibility, I outline common causes and step-by-step recovery techniques, including OCR options. Best practices to prevent content from becoming unreadable to humans and machines are also discussed.

Table of Contents

Why some URLs show no readable text

When a web link appears to contain only an image or inaccessible content, it prevents automated tools, search engines, and assistive technologies from extracting the underlying information. This undermines discoverability, harms SEO, and excludes users who rely on screen readers or text-based workflows.

Understanding the root causes is the first step to fixing the issue efficiently. It is also key to ensuring long-term accessibility and compliance with web standards.

Common causes of inaccessible content

Below are the frequent scenarios I encounter in scientific publishing and digital archiving:

Image-only PDFs or scans: Historical papers or scanned documents often exist as images without embedded text layers, so crawlers and screen readers see only pixels.

Content behind authentication or paywalls: If the page requires login or uses anti-scraping measures, automated extraction fails.

Javascript-rendered text: Some sites render content client-side in a way that bots or tools without a full browser can’t read.

No alt text or metadata: Images without alt attributes convey nothing to assistive tech or search engines.

Robots.txt or restrictive headers: Server rules might explicitly disallow crawling, blocking automated access.

How to recover text from image-only pages

If you encounter a URL that returns only an image, there are practical recovery paths depending on whether you are the content owner or a researcher trying to extract information.

Choose the approach that fits your permissions and technical context.

Tools and workflows to extract readable text

Optical Character Recognition (OCR) is the primary method for converting images of text into machine-readable content.

For best results:

Use established OCR engines such as Tesseract (open-source) or commercial services like Google Cloud Vision and ABBYY that handle scientific notation and complex layouts.

Preprocess images: increase contrast, deskew pages, and remove noise to improve OCR accuracy.

Run a quality review to correct misrecognized characters, especially in equations, tables, and special symbols common in scientific literature.

Where possible, obtain original source files (Word, LaTeX, or publisher PDFs with text layers) to avoid OCR altogether.

Best practices to prevent inaccessible content

Adopt these practices to ensure your content remains discoverable and usable.

Checklist for publishers and researchers

Publish with text layers: Export PDFs with selectable text or supply HTML versions for every article.

Include semantic markup and metadata: Add descriptive titles, headings, and structured metadata for SEO and machine readability.

Add alt text and accessible figures: Provide captions and machine-readable descriptions for images, equations, and charts.

Open access options and clear licensing: When possible, allow crawling and provide APIs or bulk access for researchers.

Here is the source article for this story: Extreme Weather California