GPT-5.1 pricing
OpenAI ·
gpt-5.1 ·
272K context
· 57th cheapest of 89 current models
Estimate GPT-5.1 for your workload Source and check date
Rates last checked against the vendor’s own published pricing on 2026-11-10.
What GPT-5.1 costs
| Rate | Per 1M tokens | Per 1K tokens | What it covers |
|---|---|---|---|
| Input | $1.25 | $0.00125 | Every token you send: prompt, history, documents. |
| Output | $10 | $0.01 | Every token the model generates, including hidden reasoning tokens. |
| Cached input | $0.125 | $0.000125 | Input served from the provider’s prompt cache. |
What that means in practice
The same three workloads are costed on every model page, so these numbers are directly comparable across the catalog. No prompt caching and no batch discount is assumed — the figures are what you pay before you optimize anything.
Support chatbot
2,500 six-turn conversations a day
$6,553 / month
$0.087 per conversation · $78,638 a year
An 800-token system prompt, 400-token questions and 900-token answers, over six turns — each turn re-sending everything before it.
Document summarizer
1,000 single-shot summaries a day
$698 / month
$0.023 per conversation · $8,370 a year
One 12,000-token document in, an 800-token summary out, no conversation history. The case where input dominates the bill.
Coding agent
200 twelve-turn sessions a day
$4,185 / month
$0.698 per conversation · $50,220 a year
A 3,000-token system prompt, 1,500-token instructions and 2,500-token responses over twelve turns. Long sessions are where the quadratic cost of re-sent history stops being theoretical.
Change the assumptions in the calculator
Cheaper, and scored at least as capable
Every model below costs less on a blended rate and carries a capability score at least as high as GPT-5.1’s. The score is a rough estimate, not a benchmark — treat it as a shortlist, not a verdict.
| Model | Input | Output | Blended saving | |
|---|---|---|---|---|
| GPT-6.1 Terra | $1 | $5 | 42% | |
| DeepSeek V4 Flash | $0.3 | $1.2 | 85% | |
| MiMo V2.6 Pro | $0.435 | $0.87 | 84% | |
| GLM-5.3 | $1.4 | $4.4 | 37% | |
| Qwen 3.8 Max | $2 | $6 | 13% |
Head to head
Specification
| Context window | 272K tokens |
|---|---|
| Maximum output | 128K tokens |
| Provider | OpenAI |
| Status | Current |
| Reasoning model | Yes |
| Vision | Yes |
| Token counting | Exact, via o200k_base |
Price history
PromptSpend has recorded GPT-5.1 since 2026-08-02, and none of its rates has changed in that time. Tracking began on 2026-08-02, so anything the vendor did before then is not on record here.
Every row, with the commit that published it, is in the price-history dataset; price news is also available as an Atom feed.
Where these numbers come from
Last checked against its source on 2026-11-10. Source of record: the vendor’s own published pricing.
The vendor page a human checked
Regional and data-residency premiums, priority tiers, server-side tool fees and negotiated discounts are not included. Prices change without notice; this page is rebuilt every time the catalog does.
Common questions
How much does GPT-5.1 cost?
GPT-5.1 costs $1.25 per 1M input tokens and $10 per 1M output tokens at the standard tier, as last checked against the vendor’s own published pricing on 2026-11-10.
How much does GPT-5.1 cost to run for a month?
On PromptSpend's three standard workloads, GPT-5.1 costs about $6,553 for a support chatbot, $698 for a document summarizer and $4,185 for a coding agent each month. No prompt caching and no batch discount is assumed, and the same workloads are costed on every model page, so the figures compare directly.
Is there a cheaper alternative to GPT-5.1?
Yes. GPT-6.1 Terra ($1 in, $5 out), DeepSeek V4 Flash ($0.3 in, $1.2 out) and MiMo V2.6 Pro ($0.435 in, $0.87 out) cost less on a blended rate and carry a capability score at least as high. The score is a rough estimate, not a benchmark, so treat the list as a shortlist.
How large is the context window of GPT-5.1?
GPT-5.1 accepts up to 272K tokens of context and can produce up to 128K tokens of output.
Has the price of GPT-5.1 changed?
No vendor change is on record. PromptSpend has recorded GPT-5.1 since 2026-08-02 and none of its rates has moved. PromptSpend began tracking prices on 2026-08-02, so earlier changes are not on record.
Where do the prices for GPT-5.1 come from?
They come from the vendor’s own published pricing and were last checked on 2026-11-10. Regional and data-residency premiums, priority tiers, server-side tool fees and negotiated discounts are not included.