DeepSeek V4 Pro
The paid one I reach for when a job spans more than one file.
Tested 2026-11-08
V4 Pro is the model I pay for. It is not the cheapest thing in my stack and it is not the one I use for a quick script. It is the one I switch to when a fix touches six files at once, when a bug only shows up in the gap between two systems, or when the answer has to be right the first time because it is going live.
Pricing is $0.66 per million input tokens and $1.98 per million output tokens, with cached input at $0.022 per million. That cache number is the whole reason it stays affordable for me: a long set of notes read once and reused all session costs almost nothing after the first pass.
Pros
- Holds a whole project in context without losing the thread mid-task
- Cached input at $0.022/M makes long reused context nearly free
- Handles multi-file edits and cross-system debugging in one pass
- Good at saying what it does not know instead of inventing it
Cons
- Output at $1.98/M is 3.3x V4.1 Flash, so a chatty answer costs real money
- Slower to first token than the small local model
- Requires network and a paid key, so it is useless on a plane
What I tested
| Test | Result |
|---|---|
| Long document summary | TODO: run the 40-page test doc and record time plus any dropped facts. |
| Coding task | Multi-file refactor across a static site generator: edits landed in all changed files, nothing outside the task touched. First run. |
| Hard reasoning | TODO: record the multi-step question, the answer, and whether it was right. |
| Image understanding | TODO: not tested yet. Text-only prompts so far. |
| Cost for a week of real use | Priced at $0.66/M in, $1.98/M out, $0.022/M cached in. A 100K-token prompt with a 5K-token answer costs about $0.08 before caching. |
Bottom line: Worth paying for on the jobs that go live. Not worth using for a one-line fix, where the local model is free and fast enough.
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