GPT-6.1 Sol vs Gemini 3.8 Flash
There is no quality verdict yet: the AIGROW small-business benchmark has not run GPT-6.1 Sol. On price, Gemini 3.8 Flash costs less: $0.75 in and $3.75 out per million tokens, against $2 in and $10 out for GPT-6.1 Sol.
US dollars, standard rate, shortest context band. Price only: the benchmark has not run both.
- GPT-6.1 Sol
- $10.00
- Gemini 3.8 Flash
- $3.75
- GPT-6.1 Sol, per M tokens
- $2 / $10
- Gemini 3.8 Flash, per M tokens
- $0.75 / $3.75
3,000 tokens in and 400 out each, at list price.
OpenAI's and Google's workhorses, with Flash well under half the Sol price until it doubles in 2027. 1,000 support replies cost $10.00 on GPT-6.1 Sol and $3.75 on Gemini 3.8 Flash, so GPT-6.1 Sol costs 2.7 times as much. GPT-6.1 Sol was released on 29 Sep 2026, Gemini 3.8 Flash was released on 2 Sep 2026.
What each one costs
The API price per million tokens and the cheapest app plan with each model, from the makers’ own pages. Each name opens that model’s full price page.
- GPT-6.1 Sol
- On the OpenAI API, GPT-6.1 Sol costs $2 per million input tokens and $10 per million output tokens. In ChatGPT, the cheapest plan with it is Plus at $20/mo. Plan prices read 14 October 2026. AIGROW API credit runs GPT-6.1 Sol at $1.00 / $6.25 per million input / output tokens, up to 50% below list price. See API credit
- Gemini 3.8 Flash
- On the Google API, Gemini 3.8 Flash costs $0.75 per million input tokens and $3.75 per million output tokens.
Side by side
Each maker’s published rate for its standard tier. Cached input is what a repeated prompt prefix costs once the provider has stored it.
| Fact | GPT-6.1 Sol | Gemini 3.8 Flash |
|---|---|---|
| Maker | OpenAI | |
| Tier | Workhorses | Workhorses |
| Input, per M tokens | $2.00 | $0.75 |
| Output, per M tokens | $10.00 | $3.75 |
| Cached input | $0.10 | $0.075 |
| Context window | 1.05M | 1.05M |
| Released | 29 Sep 2026 | 2 Sep 2026 |
| Weights | Closed weights | Closed weights |
What a job costs on each
1,000 runs of each job at the two list prices. The gap moves from job to job because the models price input, output and cached context differently.
| Job | GPT-6.1 Sol | Gemini 3.8 Flash | Cheaper |
|---|---|---|---|
| Support reply3,000 in, 400 out. | $10.00 | $3.75 | Gemini 3.8 Flash, 63% less |
| Document summary25,000 in, 1,000 out. | $60.00 | $22.50 | Gemini 3.8 Flash, 63% less |
| Agent task80,000 in (70,000 cached), 3,000 out. | $57.00 | $24.00 | Gemini 3.8 Flash, 58% less |
The token counts are ours, chosen to look like real work; the prices are the makers’. A model with no published cache price bills the agent task’s repeated context at its full input rate.
The small print
What each base rate leaves out, from the makers’ own pages: surcharges, discounts, promotions and cache pricing.
- GPT-6.1 Sol
- OpenAI recommends it to balance intelligence and cost. Requests above 272K input tokens bill 2x input and 1.5x output ($4 / $15, cached $0.20). Cache write $2.50. Batch and Flex 50% off, Fast mode 2x, Ultrafast mode $12 / $60. Data residency adds 10%. Context 1,050,000 with max input 922K. OpenAI’s pricing page
- Gemini 3.8 Flash
- Launch price through 2026-12-31; from 2027-01-01 it becomes $1.50 / $7.50, cached $0.15. Batch and Flex 50% off; Priority $1.35 / $6.75. Cache storage $0.50 per MTok per hour (rising to $1.00). Google’s pricing page
Other comparisons
Every head to head on the list that involves GPT-6.1 Sol or Gemini 3.8 Flash.
Run GPT-6.1 Sol up to 50% below list price
AIGROW API credit covers GPT-6.1 Sol at published rates never above the list prices here, and $25 buys $100 of credit.
Prices checked 15 October 2026