DeepSeek V4 Pro vs GPT-5.6 Sol
DeepSeek V4 Pro is the better buy: the AIGROW small-business benchmark cannot tell the two apart, and DeepSeek V4 Pro has the lower list price. DeepSeek V4 Pro passed 18 of 20 tasks and costs $1.32 in and $3.96 out per million tokens; GPT-5.6 Sol passed 17 and costs $4 in and $20 out.
AIGROW credit covers Claude Opus 5.5, Claude Fable 5.2, Claude Fable 5.1, GPT-6 Astra, Claude Sonnet 5.5, GPT-6.1 Sol, GPT-6.1 Terra, Grok 4.7 and Gemini 4 Argon. GPT-6 Astra below list price
$25 a month brings $110 of API credit and cancels any time; $25 once buys $100. US dollars, standard rate, shortest context band. Cost per pass from the AIGROW small-business benchmark. Newer model: GPT-6.1 Sol
- DeepSeek V4 Pro
- $5.14
- Tasks passed
- 18 of 20
- GPT-5.6 Sol
- $11.33
- Tasks passed
- 17 of 20
AIGROW small-business benchmark, failed runs included.
Shows how much quality a buyer gives up, if any, for a model that costs a fraction of Sol. DeepSeek V4 Pro costs $5.14 per 1,000 passing answers on the AIGROW small-business benchmark, GPT-5.6 Sol $11.33. 1,000 support replies cost $20.00 on GPT-5.6 Sol and $5.54 on DeepSeek V4 Pro, so GPT-5.6 Sol costs 3.6 times as much.
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.
- DeepSeek V4 Pro
- On the DeepSeek API, DeepSeek V4 Pro costs $1.32 per million input tokens and $3.96 per million output tokens.
- GPT-5.6 Sol
- On the OpenAI API, GPT-5.6 Sol costs $4 per million input tokens and $20 per million output tokens. In ChatGPT, the cheapest plan with it is Plus at $20/mo. Plan prices read 22 October 2026.
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 | DeepSeek V4 Pro | GPT-5.6 Sol |
|---|---|---|
| Maker | DeepSeek | OpenAI |
| Tier | Flagships | Flagships |
| Input, per M tokens | $1.32 | $4.00 |
| Output, per M tokens | $3.96 | $20.00 |
| Cached input | $0.044 | $0.40 |
| Context window | 1M | 1.05M |
| Released | 13 Aug 2026 | 9 Jul 2026 |
| Weights | Open 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 | DeepSeek V4 Pro | GPT-5.6 Sol | Cheaper |
|---|---|---|---|
| Support reply3,000 in, 400 out. | $5.54 | $20.00 | DeepSeek V4 Pro, 72% less |
| Document summary25,000 in, 1,000 out. | $36.96 | $120 | DeepSeek V4 Pro, 69% less |
| Agent task80,000 in (70,000 cached), 3,000 out. | $28.16 | $128 | DeepSeek V4 Pro, 78% 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.
- DeepSeek V4 Pro
- Peak-hour rate, recorded as the list price. Off-peak (all hours outside 01:00-04:00 and 06:00-10:00 UTC on weekdays) is half: $0.66 / $1.98, cache hit $0.022. Peak and off-peak pricing started 2026-08-16. API name deepseek-v4-pro serves DeepSeek-V4-Pro-0813 (V4 first shipped 2026-04-24). Max output 384K. DeepSeek’s pricing page
- GPT-5.6 Sol
- Promotional price since 2026-08-21, 'available until November 30, 2026'; the previous price was $5 / $30. Requests above 272K input tokens bill 2x input and 1.5x output ($8 / $30). Cache write $5. Batch and Flex 50% off. Data residency adds 10%. OpenAI’s pricing page
Other comparisons
Every head to head on the list that involves DeepSeek V4 Pro or GPT-5.6 Sol.
Compare DeepSeek V4 Pro and GPT-5.6 Sol with 52 other models
The price list sets every model’s input and output price side by side, with what a support reply, a document summary and an agent task cost on each.
Prices checked 12 November 2026