Productivity comparison
Grammarly vs Sonaopus
Business writing, grammar, tone, and communication quality across apps · Structuring HR, EA, project, recruiting, and real-estate situations into prompts that produce usable documents
| Decision point | Grammarly | Sonaopus |
|---|---|---|
| Best for | Business writing, grammar, tone, and communication quality across apps | Structuring HR, EA, project, recruiting, and real-estate situations into prompts that produce usable documents |
| Category | Productivity | Productivity |
| Price | Free + paid plans | $99 one-time per profession (five products) |
| AIToolsEssentials editorial score | 4.4/5 | 4.1/5 |
Scores are editorial product assessments — job fit, likely output quality, ease of adoption, and operational cost — not lab benchmarks, and no tool here has a published hands-on result. How we score.
Evidence status
Free: $0/month and 100 generative-AI prompts per month. Pro: displayed at $12 USD and includes 2,000 AI prompts per member per month, unlimited personalized suggestions, full-sentence rewrites, tone controls, plagiarism checking, and AI-generated-text detection. Enterprise: contact sales and includes unlimited prompts per member per month plus enterprise controls. The extracted pricing page did not unambiguously expose the billing cadence attached to the displayed $12 Pro amount.
Official sources checked 2026-08-25Open verification questions
- The billing cadence represented by the $12 Pro price was not rendered unambiguously in the retrieved official pricing text.
- Grammarly's exact treatment may differ for negotiated Enterprise agreements, which are governed by a separate Customer Business Agreement rather than the public self-service terms.
Official sources confirm AI drafting, rewriting, tone adjustment, fluency suggestions, grammar assistance, plagiarism checking, and AI-text detection. For Free, Premium, and single-user Pro accounts, Product Improvement and Training is enabled by default, but users can opt out; when disabled, user content is not used for model training, validation, or product improvement. Multi-user accounts bought directly online are also enabled by default, with an administrator opt-out. Enterprise-tier, sales-purchased Pro/Business, and Education accounts have training disabled by default. Grammarly says its external LLM service providers may receive prompts and context to provide generative features but may not train their models on user content. Under the October 29, 2025 Superhuman terms, inputs and outputs are User Content, and users own all right, title, and interest in User Content; the terms also grant Superhuman a broad license for operating, improving, customizing, and developing its services.
$99 USD one-time per profession-specific product, no subscription and no recurring charge. Five products: HR Management, Executive Assistant, Project Management, Real Estate, Recruiting. Free tier: up to eight generations per profession before purchase, with no signup or card. Lifetime access covers future updates to that profession's tool. Terms state that except where required by law all purchases are final and no refunds are offered, with the free trial given as the reason. A stale third-party mirror (devadex.com) still lists a retired pre-launch $59 price; the mirrored store account sonaopusaiworkflow.gumroad.com now returns 404 and the price on every live vendor page is $99.
Official sources checked 2026-09-12Open verification questions
- The homepage FAQ answer “Nothing stored” contradicts the Privacy Policy, which correctly says workflow inputs are kept in your browser's local storage. The vendor agreed in writing on 2026-09-12 to correct the more absolute wording but the homepage copy still carries it as of 2026-09-13.
- No service address or city/country is published for the seller or data controller; the vendor declined to publish one beyond the Nigeria governing-law clause. The operator name is disclosed.
- The legal-review disclosure for legally sensitive outputs (ER case documents, offer letters, contracts, HR policies) appears inside workflow prompts rather than as a standalone, findable FAQ entry.
- No data-export feature exists for locally stored workflow data; the Privacy Policy states this and directs users to contact support.
- A stale third-party mirror (devadex.com) continues to advertise a retired $59 pre-launch price for the HR product. The mirrored Gumroad account now 404s; the mirror is outside the vendor's direct control.
- Affiliate program terms are advertised at 40% on the vendor site and via Gumroad, but no written program terms (cookie window, attribution, payment terms) were published for review.
Submitted via /submit-tool.html by the vendor on 2026-09-09 and held pending verification. The vendor published /privacy and /terms on 2026-09-12 and answered every outstanding question, so the listing was published 2026-09-13 with remaining caveats recorded in cons and unresolved_claims. Editorial entry written independently; no submission copy was reused. Verified on 2026-09-13: both legal pages live and substantive; all five Gumroad products at $99 with no subscription; shipped JavaScript writes only sonaopus_hr/_ea/_pm/_re/_role to localStorage, makes zero fetch/XHR/sendBeacon calls, and has no third-party script tags; handoff targets claude.ai/new, chatgpt.com/ and gemini.google.com/ carry no query parameters. Operator: Praise Boyinde, sole proprietor, no registered entity, governing law Nigeria. The domain publishes no MX records, so the Gmail address printed in both legal pages is the only reachable contact.
How to decide
Match each platform to your actual workflow constraints. Run one real workflow in each finalist before paying.
Quick recommendation
Use the trial checklist on each review page and the free scorecard to record time-to-result, corrections needed, and monthly cost at your expected volume before committing to a plan.