speller

A speller is a person who spells words, and in modern contexts also a software tool that checks and corrects spelling in text. Spellers operate by comparing words to a dictionary and applying language-specific rules to identify misspellings and propose corrections. They are integrated into word processors, email clients, web browsers, and mobile keyboards, and are essential for editing and publishing.

Historically, spellers existed as human typists and in spelling primers; in computing, spell-checking emerged in word-processing software during the late 20th century. Early programs used simple dictionary lookups, while later systems added affix rules, stemming, and morphological analysis to handle inflections and compounds. Modern spellers may include context-based suggestions, language detection, and hyphenation guidance, and can be customized with user dictionaries.

Common speller engines include open-source projects such as Ispell, Hunspell, and Enchant, as well as commercial implementations used by major software suites. They support many languages and scripts, from Latin alphabets to non-Latin writing systems, and often rely on portable dictionaries and affix files. In practice, spellers are used for real-time input correction, batch proofreading, and accessibility tools.

Limitations include reliance on dictionary coverage, handling of proper nouns and technical terms, and potential false positives or missed errors. Some advanced systems integrate spelling with grammar and style checks, while others focus strictly on misspellings. As natural language processing advances, spellers increasingly incorporate context-aware and, in some cases, machine learning-based approaches to improve suggestion quality.