Overview
Blindspot is a web application that checks English writing with AI and explains the grammar behind each correction. Rather than returning a silently fixed sentence, it shows what changed and why, then converts recurring errors into targeted practice. The product targets intermediate and advanced learners, students, and professionals who write in English daily, and it ships a bilingual interface in English and Russian backed by a free entry tier that requires no payment card.
Key Features
AI writing checks with rule explanations. A learner pastes text into the checker and receives feedback split into a Correction block and a Why it changes block. The published example shows "didn't saw" corrected to "didn't see," with an explanation that "didn't" already marks the past tense, so the following verb stays in its base form. The landing page form accepts between 30 and 300 characters, while the in-account checker handles texts up to 5,000 characters, which covers emails, essays, and longer messages. Analysis is performed by sending submitted text to OpenAI, and both the text and the result are stored in the user's account.
Personal vocabulary building. During a check, Blindspot surfaces words worth keeping, such as a Russian phrase with suggested English equivalents, and lets the learner decide which entries enter the personal dictionary. Saved words come with a definition, part of speech breakdowns for noun and verb forms, a usage example, a collocation list, and grouped synonyms. The design keeps the dictionary curated rather than inflated by every suggestion the model produces.
Grammar practice generated from real mistakes. The platform clusters individual errors under a shared topic. Three separate sentences using "didn't saw," "didn't went," and "didn't understood" are grouped into a lesson on Past Simple negative sentences, followed by a rule statement and an interactive question with multiple answer options plus a check answer control. Practice therefore reflects patterns a learner actually repeats rather than a generic curriculum.
Chrome extension for browsing. The extension adds two workflows to the browser. Selecting a word and clicking the plus control saves it to the vocabulary list with a translation, and a writing check popup returns corrected text alongside grammar notes. This removes the need to leave the page being read or written.
Level testing and onboarding. A free English level test is offered for users who do not know where to begin, and the checker routes unauthenticated visitors through a Google sign in step before results are generated. A native language selection follows sign in, which shapes how explanations are framed.
Bilingual interface. The site ships English and Russian locales, with Russian glosses embedded inside vocabulary examples, pointing to a product designed around Russian speaking learners of English.
Use Cases
Everyday writing review covers short work emails, chat messages, and personal notes. A user drafting a message about a missed meeting can paste it, see that the negative past tense is malformed, and read the rule behind the fix before sending. The account level checker extends this to longer documents up to 5,000 characters.
Vocabulary development suits learners who want context bound entries instead of a generic word list. Because each saved term carries collocations, synonyms, and an example sentence, and feeds into flashcard review, the dictionary becomes a study asset tied to the learner's own output.
Targeted grammar drilling fits anyone with a persistent weak spot. Rather than working through an entire tense syllabus, a learner whose errors cluster around Past Simple negatives receives practice built directly from those sentences, which shortens the path from noticing an error to correcting it.
Differentiators
Most writing checkers optimise for the corrected sentence. Blindspot optimises for the learner's understanding, pairing every fix with a rule statement and then reusing the mistake as practice material. The combination of explanation, curated vocabulary with flashcards, and a Chrome extension that captures words in place creates a tighter loop between writing, diagnosis, and study than standalone grammar tools provide.
