OpenAI to Claude cost converter
Map an OpenAI model to the Claude model of the same tier (and back) and price the same workload on both.
gpt-6.1-sol (mid tier) maps to claude-sonnet-5-5, the same tier on the other side. On 100,000 calls of 2,000 in / 300 out, gpt-6.1-sol costs $700 a month and claude-sonnet-5-5 $700; with the 1,500-token prefix cached, $415 against $415. gpt-6.1-sol is 0% cheaper at list; quality is not measured here.
· Source: pricing table 2026-10-26 and the gateway's own tokenizer and benchmark files; your inputs never leave the browser except token counts, which are not stored
At a glance
- Direction
- OpenAI to Claude
- From → to
- gpt-6.1-sol → claude-sonnet-5-5 (same tier: mid)
- Per call: from / to
- $0.00700 / $0.00700 (computed)
- Per month at 100k calls
- $700 / $700 (computed)
- With prefix cached
- $415 / $415 (computed)
- Cheaper at list
- gpt-6.1-sol by 0% (computed)
- Request shape change
- OpenAI chat / Responses → Anthropic Messages
- Tier map
- frontier ↔ Opus 5.5 / GPT-6 Astra · mid ↔ Sonnet 5.5 / GPT-6.1 Sol · fast ↔ Haiku 5.5 / GPT-6 Luna
- Not measured
- output quality; run your eval before switching
gpt-6.1-sol vs claude-sonnet-5-5: 100,000 calls per month, 2,000 in (1,500 static) / 300 out, table 2026-10-26
| Model | Input $/1M | Output $/1M | Cached $/1M | Per month (list) | Prefix cached |
|---|---|---|---|---|---|
| gpt-6.1-sol | $2.00 | $10.00 | $0.100 | $700 | $415 |
| claude-sonnet-5-5 | $2.00 | $10.00 | $0.100 | $700 | $415 |
Converter
Both providers through one gateway: OPENAI_BASE_URL=https://tokenzero.sh/v1 and ANTHROPIC_BASE_URL=https://tokenzero.sh, each with its own key.
Questions people ask
How is the equivalent model chosen?
By tier in the pricing table: frontier, mid or fast on one side maps to the current model of the same tier on the other (Opus 5.5 / GPT-6 Astra, Sonnet 5.5 / GPT-6.1 Sol, Haiku 5.5 / GPT-6 Luna). It is a price mapping, not a quality claim.
Do I have to migrate to save?
No. The gateway's cache formatting, exact cache and in-provider cascade work on the model you already use; a provider migration is a separate decision that needs your own eval.
Can I run both providers side by side?
Yes: one gateway, two base URLs, two keys; receipts show the cost of each call on the model that served it.
What does TokenZero cost?
Free up to $500 per month of routed spend; then 15% of verified savings with a 3x-ROI-or-$0 rule. Gateway overhead is 1.52 ms p50, measured.