TL;DR — Sonnet 5 currently beats GPT-5.4 on both sides ($2/$10 vs $2.50/$15) — but that's a promo rate through Aug 31, 2026. Every number below is from our weekly-verified pricing tracker (verified 2026-08-26).
Pricing side by side (per 1M tokens, USD)
| Model | Provider | Input | Output | |-------|----------|-------|--------| | Claude Sonnet 5 | Anthropic | $2 | $10 | | GPT-5.4 | OpenAI | $2.5 | $15 |
Verified 2026-08-26 against official rate cards — the tracker keeps the change log. Note: Claude Sonnet 5 — promotional pricing through Aug 31, 2026.
What a real month costs
At a standard workload of 10M input + 2M output tokens/month:
- Claude Sonnet 5: $40.00
- GPT-5.4: $55.00
On this mix, Claude Sonnet 5 is the cheaper column (1.4× gap). Your ratio will differ — run your own mix through the LLM cost calculator.
Choose Claude Sonnet 5 if
the promo window makes Sonnet 5 strictly cheaper with frontier-adjacent quality; through Aug 31 this is close to a free lunch for mid-tier reasoning.
Choose GPT-5.4 if
you are planning past the promo window or need OpenAI-side features — GPT-5.4's rate is stable and its tier is proven at volume.
Routing decision card
- Until Aug 31, 2026: Sonnet 5 wins the price column outright — after that, re-check the tracker before trusting any comparison you read
- This is the pair where a dated price table matters most; most stale comparisons on the web get it wrong
- Router play: prefer Sonnet during promo, auto-rebalance when the rate reverts
- The router answer: most teams shouldn't hard-pick one — ClawRouters routes each request to whichever side fits it, so the comparison becomes a per-call decision instead of a bet.
Part of the LLM model comparison index. Prices move fast in 2026 — the tracker logs every change with dates.