Techniques for transforming digital text content using expressions are described. According to various implementations, a text editor system determines that digital text content of a digital document is modified via application of a particular style that differs from other digital text content of the digital document. The text editor system identifies a pattern characteristic to the modified digital text content, and generates a digital expression that identifies the pattern, and generates a style expression that combines the digital expression with a digital style that represents style attributes descriptive of the style modification applied to the modified text content. The text editor system applies the style expression to search digital text content, identify matching digital text content that matches the digital expression, and transform the matching digital text content by applying the digital style to modify the matching digital text content.