About Hugo Overview What is Hugo Hugo features Static site generators Hugo's security model Hugo and the GDPR License Installation Overview macOS Linux Windows BSD Getting started Overview Quick start Basic usage Directory structure Configuration Configure markup Glossary of terms External learning resources Content management Overview Organization Page bundles Content formats Diagrams Front matter Build options Page resources Image processing Shortcodes Related content Sections Content types Archetypes Taxonomies Summaries Links and cross references URL management Menus Static files Table of contents Comments Multilingual Syntax highlighting Templates Overview Templating Template lookup order Base templates and blocks Single page templates List templates Homepage template Section templates Taxonomy templates Pagination Content view templates Partial templates Shortcode templates Menu templates Data templates RSS templates Sitemap templates Local file templates Internal templates Render hooks Custom output formats 404 page Robots.txt Functions Overview cast collections compare crypto data debug diagrams encoding fmt global go template hugo images inflect js lang math openapi3 os partials path reflect resources safe strings templates time transform urls Methods Overview Duration Menu Menu entry Page Pages Resource Shortcode Site Taxonomy Time Quick reference Overview Emojis Functions Methods Page collections Variables Overview File variables Git variables Menu entry variables Page variables Pages variables Shortcode variables Site variables Taxonomy variables Hugo Modules Overview Configure Hugo modules Use Hugo Modules Theme components Hugo Pipes Overview Introduction Transpile Sass to CSS PostCSS PostProcess JavaScript building Babel Asset minification Concatenating assets Fingerprinting and SRI hashing Resource from string Resource from template CLI Troubleshooting Overview Audit Logging Inspection Deprecation Performance FAQs Developer tools Overview Editor plugins Front-ends Search Migrations Other projects Hosting and deployment Overview Hugo Deploy Deploy with Rclone Deploy with Rsync Host on 21YunBox Host on AWS Amplify Host on Azure Static Web Apps Host on Cloudflare Pages Host on Firebase Host on GitHub Pages Host on GitLab Pages Host on KeyCDN Host on Netlify Host on Render Contribute Overview Development Documentation Themes Maintenance FUNCTIONS STRING FUNCTIONS strings.ToLower Syntax strings.ToLower INPUT Returns string Alias lower {{ lower "BatMan" }} → batman See also strings.FirstUpper strings.Title strings.ToUpper