KISS Translator is a browser extension and Greasemonkey script that provides bilingual side-by-side translation on web pages.
The tool solves the problem of reading foreign-language content by overlaying translations directly onto web pages while preserving the original text. It works by detecting text on a page and fetching translations from a configurable backend service, then displaying both versions together. The extension supports multiple translation providers including Google, Microsoft, DeepL, OpenAI, Claude, and others, allowing users to choose their preferred service or compare results across providers. Beyond standard page translation, it handles specialized scenarios like YouTube subtitle translation with built-in subtitle merging and segmentation algorithms, input field translation via keyboard shortcuts, and hover-based word lookup with dictionary support.
Developers should choose this tool if they need a lightweight, open-source translation solution that works across multiple browsers and platforms. It suits anyone who regularly reads content in foreign languages and wants translations integrated directly into their browsing experience. The extension is designed to work on most websites without requiring custom configuration, though it also supports manual rules for site-specific optimization. The tool distinguishes itself through support for rich text translation that preserves links and formatting, AI context memory for improved translation quality, custom terminology dictionaries, and cross-client data synchronization via WebDAV or a custom worker service.
The project maintains active development with regular updates addressing new translation services and browser compatibility. The codebase shows ongoing refinement of core translation features, with particular attention to subtitle handling and AI integration. Documentation is comprehensive and available in multiple languages, reflecting consideration for an international user base. The tool continues to expand its translator backend support and adds advanced features like custom hooks and parameter configuration for power users.
