Comprehensive side-by-side LLM comparison
Seed-1.8 supports multimodal inputs. Both models have their strengths depending on your specific coding needs.
OpenAI
GPT-5 Codex, released by OpenAI in August 2025, is a coding-specialized large language model from the GPT-5 family engineered for software engineering, code generation, and agentic development workflows. It builds on GPT-5's architecture with optimizations targeting multi-file code editing, test generation, and automated debugging. GPT-5 Codex targets developers and agentic coding tools requiring a model tuned specifically for programming tasks.
ByteDance
Seed-1.8, developed by ByteDance Seed, is a generalized agentic large language model supporting text and image input, with industry-leading GUI agent capabilities and improvements in multimodal reasoning over its predecessor Seed1.5-VL. It targets information retrieval, code generation, GUI interaction, and complex agentic workflows requiring robust multimodal understanding.
4 months newer

GPT-5 Codex
OpenAI
2025-08
Seed-1.8
ByteDance
2025-12-18
Available providers and their performance metrics
GPT-5 Codex
Seed-1.8
GPT-5 Codex
Seed-1.8