SVG files are Scalable Vector Graphics defined using XML markup. Unlike static formats like JPG or PNG, SVGs render shapes mathematically, enabling smooth scaling without pixelation. Browsers display them natively, but issues arise due to malformed SVG code, unsupported browser features, incorrect server settings, or security restrictions. For instance, a single syntax error can break the entire image display.

Common reasons include invalid SVG syntax (like missing tags or unclosed elements), deprecated features (like SMIL animations not supported everywhere), or incorrect MIME types on the web server. Security restrictions in browsers like Chromium block rendering local SVGs via direct file:// paths if they contain external resources or scripts. Older browsers like Internet Explorer may lack support for newer SVG features.

While SVGs offer superb resolution independence and small file sizes, troubleshooting requires validating the file code and checking developer console errors. Support is excellent in modern browsers, but limitations exist for complex filters or scripting. Always ensure valid syntax through linters, host SVGs correctly via HTTP servers, and test across target browsers. Emerging standards continue to enhance SVG capabilities.