Ludwig

Ludwig is an AI detector tool. Ludwig combines a 300M+ sentence corpus with an AI editor, grammar check, rewriting, document chat, and AI detection. It is aimed at students, researchers, and professionals who want suggestions traceable to real published English rather than pure generation.

Ludwig is an English writing platform built around a simple premise: instead of only generating text for you, it shows how real writers have used a word, phrase, or structure across a large corpus of published material. That corpus, described as more than 300 million example sentences drawn from academic papers, books, and trusted publications, powers a contextual search that has been the product's signature feature since 2015. On top of it sits an AI editor and a set of focused tools for grammar checking, sentence rewriting, and AI detection. The company states it is EU-based and has been operating since 2014, with a team of about ten people. The core workflow is a single editor that adapts to the length of the job. Short text mode handles quick edits on emails and single sentences, while long text mode is aimed at dissertations, papers, and book-length manuscripts. Within the editor, clicking a sentence surfaces inline commands to rephrase, expand, or shift tone. Larger structural requests, such as restructuring paragraphs, adding citations, or strengthening an argument, arrive as suggestions the writer previews and approves rather than automatic replacements. A separate chat feature turns uploaded PDFs and spreadsheets into a searchable base for pulling out insights, data, or source citations while drafting. The audience is visible in the testimonials and branding: students, researchers, translators, editors, and professionals writing in English as a second language. University affiliations are displayed prominently, and the common phrases library is organized around academic writing, business communication, idioms, scheduling language, and social expressions. Against general-purpose AI writers, Ludwig leans on verifiability, since every recommendation can be traced to real usage examples. Against conventional grammar checkers, it adds contextual search and an assistant layer, though the homepage itself positions Ludwig as a lower-cost option rather than a direct feature match. A dedicated AI detector rounds out the set for users who need to check originality or verify sources. A desktop app is offered for people who want the tools without a browser tab, and the site claims compatibility with common writing applications. Registration unlocks daily free queries across the toolset, with paid Premium tiers for heavier use.