Best Grammar Checkers · head-to-head
ProWritingAid vs Grammarly
A sourced, side-by-side comparison for grammar checkers. ProWritingAid has the lower entry price. Every figure links to the vendor's own page and the date we captured it.
ProWritingAid has the lower entry price — ProWritingAid starts at $0/mo, Grammarly at $0/mo. Free tier: ProWritingAid Yes, Grammarly Yes. HIPAA: ProWritingAid No, Grammarly No.
As of 2026-06-15 · figures link to their source below
Side by side
ProWritingAid
$0/mo entryGrammarly
$0/mo entrySources — ProWritingAid: prowritingaid.com (verified 2026-06-15) · Grammarly: grammarly.com (verified 2026-06-15)
Key features
ProWritingAid: SOC 2 Security compliance assessed by third-party auditors (per trust-center); CREST-approved penetration testing; 25+ writing analysis reports covering readability, structure, pacing, and style; Fiction-specific tools: Virtual Beta Reader, Chapter Critique, Story Canvas, author comparison across 90 writers; Never uses submitted text to train algorithms; lifetime (one-time purchase) plan available
Grammarly: SOC 2 Type 2 + SOC 3 reports; ISO 27001/27017/27018/27701/42001 certified (per grammarly.com/security); GDPR and CCPA compliant (explicit statement on grammarly.com/business); Enterprise SAML SSO and SCIM provisioning for identity management; Works across many apps via browser extension and native integrations