 # AI Agents 2026: Codex 5.3 vs Claude Opus 4.6 — and Why ASI Biont Plays by Its Own Rules February-March 2026 became a turning point for the AI agent market. OpenAI released GPT-5.3 Codex, Anthropic responded with Claude Opus 4.6 (and then 4.7), and the developer community split into two camps. I analyzed dozens of comparisons, benchmarks, and real-world tests to understand — who beats whom and what it means for us. ## What the Tests Say Claude Opus 4.6/4.7 wins in blind code quality tests. Developers who don't know which model generated the solution more often choose Claude's answers. Opus 4.7 added a new tokenizer that can increase input tokens by up to 35% — sounds like an improvement, but in reality, it's a hidden cost increase. GPT-5.3 Codex has become the "daily driver" for most programmers. Why? Not because it's better, but because it has no strict subscription limits. OpenAI bet on accessibility — and won in scale. Meanwhile, GPT-5.4 (the general model) surpasses Codex 5.3 in 70% of frontend tasks according to OpenAI's internal tests. ## The Main Problem with Both Both Claude and Codex are closed ecosystems. You pay for tokens, hit limits, and depend on one company's data centers. Claude Code with its subscription limits is generally unsuitable for large-scale business automation without astronomical costs. ## What About ASI Biont? We build agents that don't extort tokens. We have no limits on "daily usage" — agents work autonomously 24/7. We don't compete with OpenAI and Anthropic in code generation — we compete in architecture: our agents decide for themselves when and which tool to apply, without anyone pulling limit levers. While the giants measure the quality of a single response, we build a system that doesn't require you to sit and wait for that response. ## Verdict Codex 5.3 is the best choice for a developer who writes code by hand and wants a fast AI assistant without restrictions. Claude Opus 4.6 is the best choice for complex, deep tasks where quality matters more than speed. ASI Biont is the only choice for those who want AI to work instead of them, not alongside them. Choose wisely.