How many tokens does refactoring a module take with AI?
A refactor a module typically takes about 792,000 tokens to build with an AI coding agent (roughly 318,000–1,795,000 depending on complexity), about $2.30 at today's GPT-4o prices ($0.9300–$5.20). This is the build-time (developer) cost, not the cost of running the finished feature.
Refactoring is context-heavy: the agent must understand the whole module and everything that depends on it to change structure without changing behaviour, then keep tests green. That wide reading pushes input tokens up.
Token & cost ranges
Cost uses GPT-4o at current prices. Verified 29 July 2026.
| Scenario | Input tokens | Output tokens | Total tokens | Est. cost |
|---|---|---|---|---|
| Low (simple) | 300,000 | 18,000 | 318,000 | $0.9300 |
| Typical | 750,000 | 42,000 | 792,000 | $2.30 |
| High (complex) | 1,700,000 | 95,000 | 1,795,000 | $5.20 |
Typical cost by model
The same typical token estimate priced across a few common coding models.
| Model | Typical cost | Range (low–high) |
|---|---|---|
| GPT-4o | $2.30 | $0.9300 – $5.20 |
| GPT-4o mini | $0.1377 | $0.0558 – $0.3120 |
| Claude Sonnet 4.6 | $2.88 | $1.17 – $6.52 |
| Gemini 2.0 Flash | $0.0918 | $0.0372 – $0.2080 |
How we estimate this
Refactoring requires the agent to hold a lot of context to change structure without breaking behaviour, then re-run tests and fix fallout. Input tokens dominate because an agent re-sends file context on every turn; output is the generated code, diffs and tests. Treat these as planning ranges, not a quote — your real usage depends on codebase size, model, prompt caching and how many iterations it takes.
Examples of this size
- Extracting a service and updating callers
- Splitting a god-object into modules
- Migrating a module to a new pattern
Estimate it with your own model
Plug in your model, complexity and prompt-caching to get a tailored range.
Frequently asked questions
How many tokens does a refactor a module take to build with AI?+
A refactor a module typically takes about 792,000 tokens to build with an AI coding agent (roughly 318,000–1,795,000 depending on complexity), about $2.30 at today's GPT-4o prices ($0.9300–$5.20). This is the build-time (developer) cost, not the cost of running the finished feature.
Is this the cost to build it or to run it?+
This is the build-time (developer) cost — the tokens an AI coding agent burns while implementing the work. Running the finished feature is a separate, usually much smaller per-request cost.
Why is the range so wide?+
Refactoring requires the agent to hold a lot of context to change structure without breaking behaviour, then re-run tests and fix fallout. Input tokens dominate because an agent re-sends file context on every turn; output is the generated code, diffs and tests. Treat these as planning ranges, not a quote — your real usage depends on codebase size, model, prompt caching and how many iterations it takes.
How can I lower the cost?+
Split large work into smaller pieces, enable prompt caching so re-sent context is billed at the cheaper cache-read rate, and use a cheaper model for routine steps. Try your own model in the Cost to build X estimator.