ATSChecker.ai is a browser-based ATS resume checker built to show how applicant tracking systems may parse and score a resume. It analyzes a resume against a specific job posting, producing a compatibility score based on keyword overlap, skills alignment, and formatting signals. Core features include readable contact information checks, experience section parsing, optimized skills section review, keyword gap analysis, formatting audits, actionable recommendations, bullet rewrites, scan history, and full ATS reports on Pro. The service supports PDF and DOCX uploads up to 10MB, provides results in about 60 seconds, and is private by design: resume parsing happens in the browser, and the original file is not stored.