📖 The AI Tool Bible

GPT Builder vs Izlo

A side-by-side look at pricing, capabilities, pros, cons, and our editorial scores.

 
GPT Builder
Agents
Izlo
Agents
TaglineOpenAI's no-code editor for spinning up custom ChatGPT agents with instructions, knowledge files, and tool calls.Prompt management platform with version control, collaboration, and an API for production deployment.
CategoryAgentsAgents
PricingPaid· Included with ChatGPT Plus ($20/mo), Team, Enterprise, and Edu plansPaid· Solo $20/mo; Pro $25/user/mo; Enterprise $39/user/mo
ModelOpenAI GPT-4o / GPT-5 (plan-dependent)Model-agnostic
Editorial score6.9 / 106.9 / 10
Use cases
custom-chatbotsinternal-assistantsknowledge-base-botsworkflow-automationapi-actions
prompt-managementversion-controlteam-collaborationprompt-testingproduction-deployment
Pros
  • No code: build a working agent in minutes from a chat conversation
  • Custom Actions call your own APIs via OpenAPI with OAuth or API-key auth
  • Built-in browsing, code interpreter, image gen, and file knowledge
  • GPT Store distribution and private org-only sharing on Team/Enterprise
  • Git-style version history and activity log for every prompt change
  • Remix sandbox isolates experiments from production prompts
  • REST API lets you swap prompts without redeploying the app
  • Built for multi-user team editing, not just solo developers
Cons
  • Locked to OpenAI's models and the ChatGPT runtime
  • Limited control over memory, tool routing, and evals vs Assistants API or AgentKit
  • Requires a paid ChatGPT subscription for both builder and end users
  • Knowledge file retrieval is a black box with no tuning knobs
  • No free tier; cheapest plan is $20/mo
  • Stingy token allowance (5K/seat) for in-app testing
  • Lighter on observability/analytics than Langfuse or Helicone
  • Supported model providers not clearly listed on the site
Websitechatgpt.comgetizlo.com
Pick GPT Builder if
  • ✅ No code: build a working agent in minutes from a chat conversation
  • ✅ Custom Actions call your own APIs via OpenAPI with OAuth or API-key auth
  • ✅ Built-in browsing, code interpreter, image gen, and file knowledge
  • ✅ GPT Store distribution and private org-only sharing on Team/Enterprise
Pick Izlo if
  • ✅ Git-style version history and activity log for every prompt change
  • ✅ Remix sandbox isolates experiments from production prompts
  • ✅ REST API lets you swap prompts without redeploying the app
  • ✅ Built for multi-user team editing, not just solo developers
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