Gemini 3.5 Flash
$982.50 / month- Input cost
- $307.50
- Output cost
- $675.00
- Per 1,000 calls
- $19.65
- Pricing profile
- standard
Source-tracked model comparison
Gemini 3.5 Flash vs GPT-4o: how do developer-assistant API costs compare?
Compare verified pricing and model limits for developer-assistant API cost across Google and OpenAI. The cost example uses a developer assistant backend workload and does not assume equal model quality.
Direct cost answer: Gemini 3.5 Flash is estimated at $982.50 per month and GPT-4o at $1,312.50 for 5,000 input tokens, 1,500 output tokens, and 50,000 monthly requests. Gemini 3.5 Flash is $330.00 lower under these assumptions. This does not identify a quality winner.
Tracked facts
Pricing and model limits
Prices are USD per 1M tokens under each model's verified default profile.
| Field | Gemini 3.5 Flash | GPT-4o |
|---|---|---|
| Provider | OpenAI | |
| API model ID | gemini-3.5-flash | gpt-4o |
| Input / 1M | $1.50 | $2.50 |
| Cached input / 1M | $0.15 | $1.25 |
| Output / 1M | $9.00 | $10.00 |
| Context window | 1,048,576 tokens | 128,000 tokens |
| Maximum output | 65,536 tokens | 16,384 tokens |
| Accepted input | text | text, image |
Example workload
Developer assistant backend cost scenario
5,000 input and 1,500 output tokens per request, 50,000 monthly requests, and 20% cached input.
GPT-4o
$1,312.50 / month- Input cost
- $562.50
- Output cost
- $750.00
- Per 1,000 calls
- $26.25
- Pricing profile
- standard
Cost result: Gemini 3.5 Flash is $330.00 lower per month for these assumptions. This is a price comparison, not a model-quality ranking.
Questions to answer before choosing
- Which model completes the target coding tasks reliably?
- How many retries are needed for acceptable output?
- Do existing SDK and cloud choices change switching cost?
What this estimate leaves out
The calculation does not compare coding quality and excludes indexing, execution sandboxes, and repository storage.
Latency, reliability, output quality, retries, regional processing, and provider-specific tool charges can change the practical decision.
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