Text compression is technology that reduces data size by exploiting redundancy in text data. On the web, algorithms like gzip, Brotli, and deflate are widely used for HTTP response compression.

gzip is the most widely adopted compression format, supported by virtually all browsers. Brotli, developed by Google, achieves 15-25% better compression ratios than gzip. Web performance optimization books cover compression effectiveness.

Text compression works by detecting repeated patterns and replacing them with shorter codes. Text files like HTML, CSS, and JavaScript achieve high compression ratios, with 60-80% size reduction expected.

For character counting, compressed data is in binary format where character count concepts do not apply. Pre-compression character count and post-compression byte count are different metrics. Data compression algorithms books provide additional context.