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 public page it was captured from — the vendor's own wherever the vendor publishes the number, otherwise the named public source — with 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 2026-09-09 · figures link to their source below
Side by side
ProWritingAid
$0/mo entryGrammarly
$0/mo entrySources — ProWritingAid: prowritingaid.com (verified 2026-09-05) · Grammarly: grammarly.com (verified 2026-09-09)
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