CustomGPT vs Stonly

Make an informed decision with our comprehensive comparison. Discover which RAG solution perfectly fits your needs.

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Priyansh Khodiyar's avatar
Priyansh KhodiyarDevRel at CustomGPT.ai

Fact checked and reviewed by Bill Cava

Published: 01.04.2025Updated: 25.04.2025

In this comprehensive guide, we compare CustomGPT and Stonly across various parameters including features, pricing, performance, and customer support to help you make the best decision for your business needs.

Overview

When choosing between CustomGPT and Stonly, understanding their unique strengths and architectural differences is crucial for making an informed decision. Both platforms serve the RAG (Retrieval-Augmented Generation) space but cater to different use cases and organizational needs.

Quick Decision Guide

  • Choose CustomGPT if: you value industry-leading accuracy with 97% benchmark score
  • Choose Stonly if: you value exceptional ease of use - 4.8/5 g2 rating with intuitive visual editor praised in 32 reviews

About CustomGPT

CustomGPT Landing Page Screenshot

CustomGPT is most accurate rag-as-a-service api for business. CustomGPT is the #1 benchmarked RAG platform that enables businesses to create powerful AI assistants trained on their specific data, offering industry-leading accuracy with reduced hallucinations and seamless integration capabilities. Founded in 2021, headquartered in Needham, Massachusetts, United States, the platform has established itself as a reliable solution in the RAG space.

Overall Rating
94/100
Starting Price
$99/mo

About Stonly

Stonly Landing Page Screenshot

Stonly is interactive knowledge base platform with enterprise ai-powered answers. Stonly is a customer support knowledge management platform with embedded AI capabilities focused on interactive step-by-step guides and help desk agent assistance. Its AI Answers feature (Enterprise-only add-on) achieves 71% self-serve success rates, but it's fundamentally a knowledge base platform with AI features—not a pure RAG-as-a-Service solution. Founded in 2017, headquartered in San Francisco, CA, the platform has established itself as a reliable solution in the RAG space.

Overall Rating
96/100
Starting Price
$249/mo

Key Differences at a Glance

In terms of user ratings, both platforms score similarly in overall satisfaction. From a cost perspective, CustomGPT starts at a lower price point. The platforms also differ in their primary focus: AI Chatbot versus Knowledge Management. These differences make each platform better suited for specific use cases and organizational requirements.

⚠️ What This Comparison Covers

We'll analyze features, pricing, performance benchmarks, security compliance, integration capabilities, and real-world use cases to help you determine which platform best fits your organization's needs. All data is independently verified from official documentation and third-party review platforms.

Detailed Feature Comparison

Features
logo of customGPT logo
CustomGPT
logo of stonly
Stonly
Data Ingestion & Knowledge Sources
  • 1,400+ file formats – PDF, DOCX, Excel, PowerPoint, Markdown, HTML + auto-extraction from ZIP/RAR/7Z archives
  • Website crawling – Sitemap indexing with configurable depth for help docs, FAQs, and public content
  • Multimedia transcription – AI Vision, OCR, YouTube/Vimeo/podcast speech-to-text built-in
  • Cloud integrations – Google Drive, SharePoint, OneDrive, Dropbox, Notion with auto-sync
  • Knowledge platforms – Zendesk, Freshdesk, HubSpot, Confluence, Shopify connectors
  • Massive scale – 60M words (Standard) / 300M words (Premium) per bot with no performance degradation
  • ✅ PDF uploads & public website crawling – Zendesk help center content indexing supported
  • ✅ Proprietary interactive guide format – Primary content model with visual editor
  • ⚠️ No cloud storage integrations – Missing Google Drive, Dropbox, Notion, SharePoint, YouTube
  • Content limits: Basic (5 guides, 400 views/mo), Small Business (unlimited, 4K views/mo), Enterprise (custom)
Integrations & Channels
  • Website embedding – Lightweight JS widget or iframe with customizable positioning
  • CMS plugins – WordPress, WIX, Webflow, Framer, SquareSpace native support
  • 5,000+ app ecosystem – Zapier connects CRMs, marketing, e-commerce tools
  • MCP Server – Integrate with Claude Desktop, Cursor, ChatGPT, Windsurf
  • OpenAI SDK compatible – Drop-in replacement for OpenAI API endpoints
  • LiveChat + Slack – Native chat widgets with human handoff capabilities
  • ✅ Deep help desk integrations – Zendesk, Salesforce Service Cloud, Freshdesk, ServiceNow
  • ✅ Zapier integration – Webhook triggers for form submissions and completions
  • ✅ Analytics integrations – Segment, Google Analytics
  • ⚠️ No messaging integrations – Missing Slack, WhatsApp, Telegram, Microsoft Teams
Core Chatbot Features
  • ✅ #1 accuracy – Median 5/5 in independent benchmarks, 10% lower hallucination than OpenAI
  • ✅ Source citations – Every response includes clickable links to original documents
  • ✅ 93% resolution rate – Handles queries autonomously, reducing human workload
  • ✅ 92 languages – Native multilingual support without per-language config
  • ✅ Lead capture – Built-in email collection, custom forms, real-time notifications
  • ✅ Human handoff – Escalation with full conversation context preserved
  • ✅ Interactive step-by-step guides – Visual flow builder with branching logic
  • ✅ Decision trees and checklists – Task management with progress tracking
  • ✅ Contact forms and lead capture – Integrated customer information collection
  • ✅ Multi-language support – Auto-translation on Enterprise plan
Customization & Branding
  • Full white-labeling included – Colors, logos, CSS, custom domains at no extra cost
  • 2-minute setup – No-code wizard with drag-and-drop interface
  • Persona customization – Control AI personality, tone, response style via pre-prompts
  • Visual theme editor – Real-time preview of branding changes
  • Domain allowlisting – Restrict embedding to approved sites only
  • ✅ Visual no-code editor – Intuitive interface for guides, decision trees, forms
  • ✅ CSS customization on all paid plans – White-labeling Enterprise only
  • ✅ Small learning curve – Users create guides in under 30 minutes
  • ⚠️ Cannot edit on mobile devices – Desktop-only guide creation
L L M Model Options
  • GPT-5.1 models – Latest thinking models (Optimal & Smart variants)
  • GPT-4 series – GPT-4, GPT-4 Turbo, GPT-4o available
  • Claude 4.5 – Anthropic's Opus available for Enterprise
  • Auto model routing – Balances cost/performance automatically
  • Zero API key management – All models managed behind the scenes
  • ⚠️ Undisclosed proprietary LLM – No model selection or transparency on provider
  • ✅ AI Profiles (20) & Custom Instructions (100) – Define tone, boundaries, behavior
  • ✅ Guided AI Answers – Predefined responses for sensitive scenarios bypass AI
  • ✅ Knowledge-grounded approach – Anchored responses reduce hallucinations vs generic chatbots
Developer Experience ( A P I & S D Ks)
  • REST API – Full-featured for agents, projects, data ingestion, chat queries
  • Python SDK – Open-source customgpt-client with full API coverage
  • Postman collections – Pre-built requests for rapid prototyping
  • Webhooks – Real-time event notifications for conversations and leads
  • OpenAI compatible – Use existing OpenAI SDK code with minimal changes
  • ✅ REST API – User provisioning, content management, widget control
  • ✅ Mobile SDKs (Enterprise only) – iOS, Android, React Native, Flutter
  • ⚠️ No Python/Node.js SDKs – No GraphQL, OpenAPI specs, or API sandbox
Performance & Accuracy
  • Sub-second responses – Optimized RAG with vector search and multi-layer caching
  • Benchmark-proven – 13% higher accuracy, 34% faster than OpenAI Assistants API
  • Anti-hallucination tech – Responses grounded only in your provided content
  • OpenGraph citations – Rich visual cards with titles, descriptions, images
  • 99.9% uptime – Auto-scaling infrastructure handles traffic spikes
  • ✅ 71% self-serve success rate – Company data with AI Answers feature
  • ✅ 70-76% ticket reduction – Documented in case studies
  • ✅ 99.9% uptime claimed – No published SLA or response time details
  • ⚠️ Flow reports update every 15 min – Not real-time analytics
Security & Compliance
  • SOC 2 Type II + GDPR – Regular third-party audits, full EU compliance
  • 256-bit AES encryption – Data at rest; SSL/TLS in transit
  • SSO + 2FA + RBAC – Enterprise access controls with role-based permissions
  • Data isolation – Never trains on customer data
  • Domain allowlisting – Restrict chatbot to approved domains
  • ✅ SOC 2 Type 2, GDPR, HIPAA, ISO 27001 – PCI, CSA Star Level 1
  • ✅ Trust Center – trust.stonly.com with documentation, subprocessor lists
  • ✅ SAML 2.0 SSO (Enterprise) – IP allowlisting, advanced RBAC, 2FA
  • ⚠️ Data residency not documented – May limit certain jurisdiction deployments
Pricing & Plans
  • Standard: $99/mo – 10 chatbots, 60M words, 5K items/bot
  • Premium: $449/mo – 100 chatbots, 300M words, 20K items/bot
  • Enterprise: Custom – SSO, dedicated support, custom SLAs
  • 7-day free trial – Full Standard access, no charges
  • Flat-rate pricing – No per-query charges, no hidden costs
  • Basic (Free): 5 guides, 400 views/mo, 1 seat, single language
  • Small Business ($249/mo, $199/mo annual): Unlimited guides, 4K views/mo, 5 seats, CSS customization
  • Enterprise (~$39K/year avg): Custom views, unlimited seats, white-label, SAML SSO, Mobile SDKs
  • ⚠️ Overage pricing: +15K views = $200/mo, auto-upgrade after 2 consecutive months
Support & Ecosystem
  • Comprehensive docs – Tutorials, cookbooks, API references
  • Email + in-app support – Under 24hr response time
  • Premium support – Dedicated account managers for Premium/Enterprise
  • Open-source SDK – Python SDK, Postman, GitHub examples
  • 5,000+ Zapier apps – CRMs, e-commerce, marketing integrations
  • ✅ 4.8/5 G2 rating (132 reviews) – Ease of use praised in 32 reviews
  • ✅ Email and chat support – Dedicated support on Enterprise plan
  • ✅ Pre-built templates – Quick onboarding, guides created in under 30 minutes
Observability & Monitoring
  • Real-time dashboard – Query volumes, token usage, response times
  • Customer Intelligence – User behavior patterns, popular queries, knowledge gaps
  • Conversation analytics – Full transcripts, resolution rates, common questions
  • Export capabilities – API export to BI tools and data warehouses
  • ✅ Insights Dashboard – Views, visitors, bounce rates, drop-off analysis
  • ✅ NPS surveys (all plans) – CSAT and CES Enterprise only
  • ✅ Data export – Segment, Zapier, Google Analytics integration
Use Cases
  • Customer support – 24/7 AI handling common queries with citations
  • Internal knowledge – HR policies, onboarding, technical docs
  • Sales enablement – Product info, lead qualification, education
  • Documentation – Help centers, FAQs with auto-crawling
  • E-commerce – Product recommendations, order assistance
  • ✅ Customer support ticket deflection – 70-76% reduction through interactive guides
  • ✅ Deep help desk integration – Zendesk, Salesforce, Freshdesk, ServiceNow workflows
  • ✅ Interactive onboarding – Step-by-step guides, decision trees, checklists
  • ✅ Multi-language support – Auto-translation for global teams (Enterprise)
Limitations & Considerations
  • Managed service – Less control over RAG pipeline vs build-your-own
  • Model selection – OpenAI + Anthropic only; no Cohere, AI21, open-source
  • Real-time data – Requires re-indexing; not ideal for live inventory/prices
  • Enterprise features – Custom SSO only on Enterprise plan
  • ⚠️ NOT a RAG-as-a-Service platform – Knowledge base tool with embedded AI
  • ⚠️ AI Answers Enterprise-gated – ~$39K/year, not available on $249/mo tier
  • ⚠️ Limited data sources – PDF, web, Zendesk only; no cloud storage
  • ⚠️ No messaging integrations – Missing Slack, WhatsApp, Telegram, Microsoft Teams
  • Not ideal for: Pure RAG API, multi-tenant SaaS backends, model customization needs
Core Agent Features
  • Custom AI Agents – Autonomous GPT-4/Claude agents for business tasks
  • Multi-Agent Systems – Specialized agents for support, sales, knowledge
  • Memory & Context – Persistent conversation history across sessions
  • Tool Integration – Webhooks + 5,000 Zapier apps for automation
  • Continuous Learning – Auto re-indexing without manual retraining
  • ✅ Knowledge-grounded responses – Verified structured knowledge prevents hallucinations
  • ✅ AI Agent Assist – Summarizes tickets, suggests paths, drafts responses
  • ✅ Process automation – Define workflows linked to back-office tools
  • ✅ 71% self-serve success rate – Personalized knowledge adapts to needs
R A G Capabilities
  • GPT-4 + RAG – Outperforms OpenAI in independent benchmarks
  • Anti-hallucination – Responses grounded in your content only
  • Automatic citations – Clickable source links in every response
  • Sub-second latency – Optimized vector search and caching
  • Scale to 300M words – No performance degradation at scale
  • ✅ AI Answers (Enterprise add-on) – Grounded in guides, websites, PDFs
  • ✅ 71% self-serve success rate – Confidence-based fallback to ML search
  • ⚠️ Limited data sources – No Google Drive, Dropbox, Notion, SharePoint, YouTube
  • ⚠️ Manual content updates – No automatic syncing from external sources
Competitive Positioning
  • Market position – Leading RAG platform balancing enterprise accuracy with no-code usability. Trusted by 6,000+ orgs including Adobe, MIT, Dropbox.
  • Key differentiators – #1 benchmarked accuracy • 1,400+ formats • Full white-labeling included • Flat-rate pricing
  • vs OpenAI – 10% lower hallucination, 13% higher accuracy, 34% faster
  • vs Botsonic/Chatbase – More file formats, source citations, no hidden costs
  • vs LangChain – Production-ready in 2 min vs weeks of development
  • ✅ Unique interactive guide format – Structured support content vs free-form chat
  • ✅ 70-76% ticket reduction – 71% self-serve success rate documented
  • vs CustomGPT: Different categories (knowledge base vs RAG-as-a-Service)
  • Target: Support teams using Zendesk/Salesforce, not RAG developers
R A G-as-a- Service Assessment
  • Platform type – TRUE RAG-AS-A-SERVICE with managed infrastructure
  • API-first – REST API, Python SDK, OpenAI compatibility, MCP Server
  • No-code option – 2-minute wizard deployment for non-developers
  • Hybrid positioning – Serves both dev teams (APIs) and business users (no-code)
  • Enterprise ready – SOC 2 Type II, GDPR, WCAG 2.0, flat-rate pricing
  • ⚠️ NOT a RAG-as-a-Service platform – Knowledge base tool with embedded AI
  • ⚠️ Limited data sources – PDF, public web, Zendesk only
  • ✅ Strong hallucination controls – Grounded in structured content
  • Best for: Customer support ticket deflection, not flexible RAG backends
A I Models
  • OpenAI – GPT-5.1 (Optimal/Smart), GPT-4 series
  • Anthropic – Claude 4.5 Opus/Sonnet (Enterprise)
  • Auto-routing – Intelligent model selection for cost/performance
  • Managed – No API keys or fine-tuning required
  • ⚠️ Undisclosed Proprietary LLM – No model selection or transparency
  • ✅ AI Profiles (20) & Custom Instructions (100) – Define tone and boundaries
  • ✅ Guided AI Answers – Predefined responses for sensitive scenarios
  • ✅ Knowledge-grounded approach – Anchored responses reduce hallucinations
No- Code Interface & Usability
  • 2-minute deployment – Fastest time-to-value in the industry
  • Wizard interface – Step-by-step with visual previews
  • Drag-and-drop – Upload files, paste URLs, connect cloud storage
  • In-browser testing – Test before deploying to production
  • Zero learning curve – Productive on day one
  • ✅ 4.8/5 ease of use rating – Visual drag-and-drop editor, no coding required
  • ✅ Small learning curve – Non-technical teams productive quickly
  • ✅ Pre-built templates – Common scenarios covered for faster creation
Customization & Flexibility ( Behavior & Knowledge)
  • Live content updates – Add/remove content with automatic re-indexing
  • System prompts – Shape agent behavior and voice through instructions
  • Multi-agent support – Different bots for different teams
  • Smart defaults – No ML expertise required for custom behavior
  • ✅ CSS and HTML customization – Change layout and look with custom code
  • ✅ Intuitive no-code tools – Easy customization without coding for basics
  • ✅ Personalized content – Use customer data for targeted experiences
  • ✅ Rich media support – Images, GIFs, videos, annotations
Pricing & Scalability
  • Standard: $99/mo – 60M words, 10 bots
  • Premium: $449/mo – 300M words, 100 bots
  • Auto-scaling – Managed cloud scales with demand
  • Flat rates – No per-query charges
  • Basic (Free): 5 guides, 400 views/mo, 1 seat, single language
  • Small Business ($249/mo, $199/mo annual): Unlimited guides, 4K views/mo, 5 seats, CSS customization
  • Enterprise (~$39K/year avg): Custom views, unlimited seats, AI Answers add-on, Mobile SDKs, SAML SSO
  • ⚠️ Overage pricing escalates – +15K views = $200/mo, auto-upgrade after 2 months
Security & Privacy
  • SOC 2 Type II + GDPR – Third-party audited compliance
  • Encryption – 256-bit AES at rest, SSL/TLS in transit
  • Access controls – RBAC, 2FA, SSO, domain allowlisting
  • Data isolation – Never trains on your data
  • ✅ SOC 2 Type 2, GDPR, HIPAA, ISO 27001 – PCI, CSA Star Level 1 compliant
  • ✅ Trust Center – trust.stonly.com with security documentation, subprocessor lists
  • ✅ SAML 2.0 SSO (Enterprise) – IP allowlisting, advanced RBAC, 2FA
Support & Documentation
  • Documentation hub – Docs, tutorials, API references
  • Support channels – Email, in-app chat, dedicated managers (Premium+)
  • Open-source – Python SDK, Postman, GitHub examples
  • Community – User community + 5,000 Zapier integrations
  • ✅ 4.8/5 G2 rating (132 reviews) – Ease of use praised consistently
  • ✅ Email and chat support – Dedicated support on Enterprise plan
  • ✅ Pre-built templates & tutorials – Guides created in under 30 minutes
Additional Considerations
  • Time-to-value – 2-minute deployment vs weeks with DIY
  • Always current – Auto-updates to latest GPT models
  • Proven scale – 6,000+ organizations, millions of queries
  • Multi-LLM – OpenAI + Claude reduces vendor lock-in
  • ⚠️ Limited UI customization – Cannot fully match specific brand requirements
  • ⚠️ No offline access – Requires internet connectivity for guide availability
  • ⚠️ Performance degradation with large guides – Scalability concerns with complexity
  • ⚠️ View-based pricing – Additional fees for exceeding 4K views/mo
Core Knowledge Base Features
N/A
  • ✅ Interactive step-by-step guides – Visual flow builder with branching logic
  • ✅ Decision trees, checklists, forms – Contact forms and lead capture
  • ✅ Content versioning – Side-by-side comparison, instant restore (Business+)
  • ✅ Multi-language support – Auto-translation on Enterprise plan
A I Answers Feature ( Enterprise Only)
N/A
  • ⚠️ Enterprise add-on only – Not included in Small Business plan
  • ✅ Generative AI grounded – Anchored in Stonly guides, websites, PDFs
  • ✅ Confidence-based fallback – Switches to ML-powered search when confidence low
  • ✅ 71% self-serve success rate – Hallucination reduction through knowledge-grounding

Final Thoughts

Final Verdict: CustomGPT vs Stonly

After analyzing features, pricing, performance, and user feedback, both CustomGPT and Stonly are capable platforms that serve different market segments and use cases effectively.

When to Choose CustomGPT

  • You value industry-leading accuracy with 97% benchmark score
  • Patented technology to reduce hallucinations
  • Easy no-code setup with powerful customization

Best For: Industry-leading accuracy with 97% benchmark score

When to Choose Stonly

  • You value exceptional ease of use - 4.8/5 g2 rating with intuitive visual editor praised in 32 reviews
  • Deep help desk integrations - bidirectional Zendesk, Salesforce, Freshdesk, ServiceNow connections
  • Strong compliance - SOC 2 Type 2, GDPR, HIPAA, ISO 27001, PCI, CSA Star Level 1

Best For: Exceptional ease of use - 4.8/5 G2 rating with intuitive visual editor praised in 32 reviews

Migration & Switching Considerations

Switching between CustomGPT and Stonly requires careful planning. Consider data export capabilities, API compatibility, and integration complexity. Both platforms offer migration support, but expect 2-4 weeks for complete transition including testing and team training.

Pricing Comparison Summary

CustomGPT starts at $99/month, while Stonly begins at $249/month. Total cost of ownership should factor in implementation time, training requirements, API usage fees, and ongoing support. Enterprise deployments typically see annual costs ranging from $10,000 to $500,000+ depending on scale and requirements.

Our Recommendation Process

  1. Start with a free trial - Both platforms offer trial periods to test with your actual data
  2. Define success metrics - Response accuracy, latency, user satisfaction, cost per query
  3. Test with real use cases - Don't rely on generic demos; use your production data
  4. Evaluate total cost - Factor in implementation time, training, and ongoing maintenance
  5. Check vendor stability - Review roadmap transparency, update frequency, and support quality

For most organizations, the decision between CustomGPT and Stonly comes down to specific requirements rather than overall superiority. Evaluate both platforms with your actual data during trial periods, focusing on accuracy, latency, ease of integration, and total cost of ownership.

📚 Next Steps

Ready to make your decision? We recommend starting with a hands-on evaluation of both platforms using your specific use case and data.

  • • Review: Check the detailed feature comparison table above
  • • Test: Sign up for free trials and test with real queries
  • • Calculate: Estimate your monthly costs based on expected usage
  • • Decide: Choose the platform that best aligns with your requirements

Last updated: January 19, 2026 | This comparison is regularly reviewed and updated to reflect the latest platform capabilities, pricing, and user feedback.

See Also

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Why Choose CustomGPT?

97% Accuracy

Industry-leading benchmarks

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CustomGPT

The most accurate RAG-as-a-Service API. Deliver production-ready reliable RAG applications faster. Benchmarked #1 in accuracy and hallucinations for fully managed RAG-as-a-Service API.

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Priyansh Khodiyar's avatar

Priyansh Khodiyar

DevRel at CustomGPT.ai. Passionate about AI and its applications. Here to help you navigate the world of AI tools and make informed decisions for your business.

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