Image Alt Text Checker
Audit HTML markup or image tags to detect missing or empty alt attributes for SEO and accessibility (WCAG).
How to Use the Image Alt Text Checker
- Enter your parameters: Type, paste, or select your input values above.
- View instant results: Calculations update in real time as you change values.
- Copy or export: Click copy, download, or print to use your results immediately.
About this Tool
Ensure all images have descriptive alternative text for Google Image Search rankings and screen reader accessibility.
Hardware-Accelerated Raster Processing
HTML5 2D Canvas & WebP/MozJPEG Quantization PipelineImages are decoded directly into an in-memory Canvas buffer. Compression algorithms optimize Huffman frequency tables and subsample chroma channels without sending pixels to a server.
Worked Example: Lossless Web Optimization Example
3.8 MB PNG product photo (3000 x 2000 px)
340 KB WebP image (91% size reduction) with 100% visual sharpness
Converting from uncompressed PNG raster to modern WebP compression cuts download time by 90% while passing Google Core Web Vitals audits.
Frequently Asked Questions
Why is WebP better than PNG for websites?
WebP supports both lossy and lossless compression, includes 8-bit alpha transparency, and typically produces file sizes 26% smaller than PNGs and 25-34% smaller than comparable JPEGs.
How does image file size impact Google Core Web Vitals?
Large hero images delay Largest Contentful Paint (LCP). Keeping hero images under 150 KB and serving modern WebP or AVIF formats guarantees fast LCP scores under 2.5 seconds.
Does resizing an image alter its aspect ratio?
By default, TTech tools preserve the original width-to-height aspect ratio to prevent stretching or distortion.
Calculation Standards
Engineered in accordance with W3C HTML Canvas and WebP compression standards. For tax, legal, or medical advice, consult certified professionals.
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