Model comparison
Grok 4.7 vs GPT-6 Sol: which costs less depends on the cache
Grok 4.7 and GPT-6 Sol launched a day apart at $2 input. GPT-6 Sol wins a cached session, $2.10 to $2.30. Grok 4.7 wins uncached and output-heavy work.
· Prices as of September 28, 2026
Grok 4.7
xAI · Released September 21, 2026
xAI's top model for coding and knowledge work, which xAI says works longer on hard tasks and checks its own work more carefully.
Grok 4.7 facts and comparisonsGPT-6 Sol
OpenAI · Released September 22, 2026
The mid-priced GPT-6 model, which OpenAI pitches for complex coding and agent workflows and which the Codex docs recommend for complex coding.
GPT-6 Sol facts and comparisons
The short answer
GPT-6 Sol costs less on the example agentic coding session, $2.10 against $2.30 on Grok 4.7, because its cache hits cost $0.20 per million against $0.50. Grok 4.7 costs less on everything uncached: its output rate is $6 against $10, so the output-heavy generation runs $0.54 against $0.86. The windows differ as well, 1.05M on GPT-6 Sol and 500K on Grok 4.7, and each has its own long-context price line, at 272K for GPT-6 Sol and 200K for Grok 4.7.
Choose Grok 4.7 if
- Your work is uncached or output-heavy: Grok 4.7 writes output at $6 per million against $10.
- You want no cache-write premium, since xAI bills written tokens as ordinary input while OpenAI charges 1.25x.
- You pick models in Cursor, whose model list credits Grok 4.7 to joint training by Cursor and xAI.
- You like xAI's pitch of a model that works longer on difficult tasks and checks its own work more carefully.
Choose GPT-6 Sol if
- You run long cached sessions, where a GPT-6 Sol hit at $0.20 per million costs well under Grok 4.7's $0.50.
- You work in Codex, whose docs recommend GPT-6 Sol for complex coding.
- Your prompts run between 200K and 272K tokens, where Grok 4.7 has already moved to its higher rates and GPT-6 Sol has not.
- You need a window beyond 500K: GPT-6 Sol offers 1.05M, with up to 922K of input.
Side by side
Specs and prices
| Fact | Grok 4.7 | GPT-6 Sol |
|---|---|---|
| Maker | xAI | OpenAI |
| API model id | grok-4.7 | gpt-6-sol |
| Released | September 21, 2026 | September 22, 2026 |
| Status | Current | Current |
| Context window | 500K tokens | 1.05M tokens |
| Max output | Not published | 128K tokens |
| Open weights | No | No |
| Input, per 1M tokens | $2 | $2 |
| Cache hit, per 1M | $0.50 | $0.20 |
| Cache write, per 1M | $2 (same as input) | $2.50 |
| Output, per 1M tokens | $6 | $10 |
| Runs in | Cursor, OpenCode, OpenRouter, and GitHub Copilot | Codex, OpenCode, OpenRouter, and GitHub Copilot |
Standard API rates in US dollars, as published by each maker on September 28, 2026. Batch and priority tiers, taxes, and subscription plans are not included. Grok 4.7: Once a prompt reaches 200K tokens, every token in the request costs $4 input, $1 cached, and $12 output per million. The US regional endpoint costs 10% more. GPT-6 Sol: Requests over 272K input tokens cost 2x for input and cache and 1.5x for output, for the whole request.
Cost
What the same work costs
The same token counts, priced at each model’s published rates. Cached tokens are billed at each maker’s cache prices, so the session shows what caching is worth on each model.
Real sessions differ: the two models count the same code as different numbers of tokens, and reasoning settings change how much each one writes. Your own history is the real test.
| Workload | Grok 4.7 | GPT-6 Sol |
|---|---|---|
| Agentic coding session, 100K input, 400K written to cache, 2M read from cache, 50K output | $2.30 | $2.10 |
| Large one-off review, 150K input with no cache hits, 10K output | $0.36 | $0.40 |
| Output-heavy generation, 30K input, 80K output | $0.54 | $0.86 |
| A month of sessions, 110 sessions: 5 a day, 22 working days | $253.00 | $231.00 |
| Where the session’s cost goes | ||
| Cache writes | $0.80 | $1.00 |
| Cache reads | $1.00 | $0.40 |
| Uncached input | $0.20 | $0.20 |
| Output | $0.30 | $0.50 |
- caching saves on the session with Grok 4.7 (57%)
- $3.00
- caching saves on the session with GPT-6 Sol (62%)
- $3.40
Launched a day apart at the same input price
xAI released Grok 4.7 on September 21, 2026, and OpenAI released GPT-6 Sol the next day. Both list $2 per million input tokens. xAI calls Grok 4.7 "our most capable model for coding and knowledge work," and OpenAI describes GPT-6 Sol, the mid-priced model of its GPT-6 family, as "built to power complex coding and agentic workflows."
The rest of the rate card splits. Grok 4.7 charges $6 per million output tokens against $10 on GPT-6 Sol, and bills cache writes as ordinary input at $2. GPT-6 Sol charges a 1.25x premium for writes, $2.50, but only $0.20 for a cache hit, 10% of input. A Grok 4.7 hit costs $0.50, or 25% of input.
Why the cheaper model flips between workloads
The example agentic session reads 2M tokens from the cache. On Grok 4.7 those reads cost $1.00, 43% of its session, and on GPT-6 Sol they cost $0.40. Grok 4.7 claws back $0.20 on writes and $0.20 on output, which leaves GPT-6 Sol ahead at $2.10 against $2.30, 9% less, or $22.00 over 110 sessions a month.
Take the cache away and the order reverses. The large one-off review, 150K input with no cache hits, costs $0.36 on Grok 4.7 and $0.40 on GPT-6 Sol. The output-heavy generation, 80K of output, costs $0.54 against $0.86, 37% less on Grok 4.7. The more your work leans on fresh output rather than cached rereads, the better Grok 4.7's rates look.
Caching mechanics differ too. OpenAI caches automatically, lets you mark up to four explicit breakpoints, and keeps a cached prefix reusable for at least 30 minutes after its last use. xAI caches repeated prefixes automatically and says that sending the same conversation id with each request raises the hit rate.
Long-context rules: 200K on Grok 4.7, 272K on GPT-6 Sol
Both makers charge more for long prompts, at different lines and by different amounts. Once a Grok 4.7 prompt reaches 200K tokens, every token in the request costs $4 input, $1 cached, and $12 output per million, double the standard rates. GPT-6 Sol requests over 272K input tokens cost 2x for input and cache and 1.5x for output, again for the whole request.
Between 200K and 272K, then, Grok 4.7 is already on its higher tier while GPT-6 Sol still bills standard rates. Past 272K both are raised, but output rises less on GPT-6 Sol. The windows end in different places: Grok 4.7 accepts 500K tokens, and GPT-6 Sol has a 1.05M window, of which up to 922K can be input. GPT-6 Sol writes up to 128K of output, and xAI publishes no output limit for Grok 4.7.
The example session keeps every request under 200K, so the cost table shows neither tier. xAI's US regional endpoint adds 10% to Grok 4.7's rates, which the table also leaves out.
Codex, Cursor, and the tools in between
GPT-6 Sol runs in Codex, OpenAI's own coding agent, whose docs recommend it for complex coding and suggest moving to it from GPT-5.6 Sol, GPT-5.6 Terra, and GPT-5.4. Its reasoning effort defaults to medium in the API and in Codex. Cursor lists Grok 4.7 as trained jointly by Cursor and xAI, and also offers a faster Grok 4.7 Fast at double the rates. Both models are in OpenCode, OpenRouter, and GitHub Copilot.
EveryToken prices GPT-6 Sol at OpenAI's rates from Codex and OpenCode history, and prices Grok 4.7 only when you use it through OpenRouter, from OpenRouter's catalog rather than the xAI API rates in these tables. Either way its figures are API-equivalent estimates at published rates, not what a subscription charges.
Prompt caching
How each maker bills cached tokens
xAI
The xAI API caches repeated prompt prefixes automatically. Sending the same conversation id with each request raises the hit rate.
xAI lists no fee for writing the cache. A cache hit costs $0.50 per million tokens on Grok 4.7 and $0.20 on Grok Build 0.1.
Source: xAI docs: Prompt caching
OpenAI
Prompt caching is on by default. From GPT-5.6 on you can also mark up to four explicit cache breakpoints, while GPT-5.5 and earlier cache automatically only.
From GPT-5.6 on, a cache write costs 1.25x the uncached input price and a cache hit costs 0.1x. GPT-5.5 and earlier add no charge for writing the cache: written tokens are billed as ordinary input, and a hit costs 0.1x on the models compared here.
On GPT-5.6 and later, a cached prefix stays reusable for at least 30 minutes after its last use, and caching starts at 1,024 input tokens.
Source: OpenAI: Prompt caching
Your own numbers
See what Grok 4.7 and GPT-6 Sol really cost you.
everyaitoken reads your OpenRouter, Codex, and OpenCode history on your Mac and prices every request at API rates, with what caching saved or cost. $9 once.
FAQ
Questions
Is Grok 4.7 cheaper than GPT-6 Sol?
It depends on caching. Uncached work costs less on Grok 4.7, whose output is $6 per million against $10. A cache-heavy agentic session costs less on GPT-6 Sol, $2.10 against $2.30, because its hits cost $0.20 against $0.50.
Which model has the larger context window?
GPT-6 Sol, with 1.05M tokens and up to 922K of input, against 500K on Grok 4.7. Grok 4.7 raises every rate once a prompt reaches 200K tokens, and GPT-6 Sol raises its rates above 272K input tokens.
Does either model charge extra to write the cache?
GPT-6 Sol does: OpenAI bills a cache write at 1.25x the input price, $2.50 per million. xAI lists no write fee, so Grok 4.7 bills written tokens at its $2 input rate.
When were Grok 4.7 and GPT-6 Sol released?
xAI released Grok 4.7 on September 21, 2026, and OpenAI released GPT-6 Sol on September 22, 2026. Both are current models, and the prices here are as of September 28, 2026.
Sources
- xAI docs: Grok 4.7
- xAI: Grok 4.7
- OpenRouter: Grok 4.7
- OpenCode docs: Zen
- Cursor docs: Models
- GitHub Docs: Supported AI models in Copilot
- OpenAI: API pricing
- OpenAI docs: GPT-6 Sol
- OpenAI: Introducing GPT-6 Sol and Luna
- OpenAI: API changelog
- Codex docs: Models
- OpenRouter: GPT-6 Sol
- OpenCode docs: Zen
- xAI docs: Prompt caching
- OpenAI: Prompt caching