GPT-5 vs Inkling

Choose GPT-5 if you want…

• ✓Larger context window (400K)

Choose Inkling if you want…

• ✓Higher intelligence (Artificial Analysis index 46)
• ✓Lower price ($1.76 / 1M blended)

GPT-5

GPT-5 is OpenAI's unified flagship — a single model that scales its reasoning effort up or down to match the task, rather than making you pick a separate variant. The result shows up most clearly in hard technical work: a perfect AIME 2025 score with tools, 74.9% on SWE-bench Verified, and a 1.6% error rate on medical benchmark HealthBench make it one of the more capable models available for code, math, and domain-specific research. Its 400,000-token context window handles large codebases and lengthy documents without truncation. Users consistently praise the step-up in accuracy and the meaningful reduction in hallucinations over GPT-4o. The honest caveat: GPT-5 trades warmth for precision. Early adopters widely noted that responses are shorter, cooler, and noticeably less conversational than its predecessor — a real shift if personality and back-and-forth rapport matter to your workflow. Latency is also substantial; extended reasoning produces a time-to-first-token around 68 seconds, which rules it out for anything requiring snappy replies.

Inkling

Inkling is Thinking Machines Lab's first open-weights model, and on just4o.chat it runs through the Vercel AI Gateway under thinkingmachines/inkling. It is a multimodal MoE with 975B total parameters and 41B active, trained to reason over text, images, and audio in a shared space rather than bolting on separate encoders. Controllable thinking effort lets you trade latency for depth, function calling supports agentic workflows, and a 256k context window on the gateway is roomy enough for long multimodal sessions. It is a base-tier model on just4o.chat, billed at 4 base requests per send before length multipliers, at $1.00 per million input and $4.05 per million output tokens (cached input $0.17). Practical caveats: no native web search on this route, and chat attachments currently emphasize image input even though the model itself understands audio. For teams that want an open, customizable multimodal foundation with ZDR-compatible gateway routing, Inkling is a strong addition.