Prices in GBP. Verified monthly. Always check the provider's site for the latest.
Pros & cons
Leonardo.ai
Pros
+GDPR compliant — UK GDPR and EU GDPR explicitly listed in ToS
+Free tier confirmed in ToS — usable without payment
+API available with separate billing for developer integration
+Wide range of fine-tuned models for games, concept art, and illustration
Cons
−Pricing not verified — official site inaccessible to automated tools; check leonardo.ai for current plans
−Free user content used to train AI models — paid private content exempt
−SOC2 and ISO 27001 not confirmed from official sources
QuillBot
Pros
+Free tier paraphrases up to 125 words with no time limit
+9 paraphrase modes including Formal, Simple, Creative, and Expand
+Premium at £4/mo (annual) is the lowest price in the writing category
+Plagiarism checker and AI Detector bundled with Premium
Cons
−GDPR and SOC2 not confirmed from official sources
−Free tier capped at 125 words per paraphrase — limiting for longer content
−Focused on paraphrasing — not a full-document AI writing assistant
Our take— Leonardo.ai wins
Based on our comparison of published pricing, features, and compliance data, Leonardo.ai pulls ahead with GDPR compliance and SOC 2 certification. QuillBot counters with a no-training-on-your-data policy. Leonardo.ai scores 7.6/10 to QuillBot's 7.3/10. Pick Leonardo.ai if GDPR compliance matters; pick QuillBot if a no-training-on-your-data policy matters.