Gemini 3.1 Flash API Pricing: Proven Multimodal Scale and Speed
Comprehensive Gemini 3.1 Flash API pricing analysis ($0.75/M input, $4.50/M output), multimodal vision/audio benchmarks, prompt caching breaks, and upgrade paths.
How much does Gemini 3.1 Flash cost per million tokens?
Gemini 3.1 Flash costs $0.75 per million input tokens and $4.50 per million output tokens ($1.6875/M blended at 3:1). Offers high-throughput multimodal intelligence for text, images, and audio with 1M context. Verified 2026-09-08.
How much does Gemini 3.1 Flash cost per 1,000 requests?
Computed from generated token pricing. Each row assumes the listed input and output tokens per request; this model has no measured verbosity factor, so the unadjusted output estimate is shown.
| Request shape | Input tokens | Output tokens | Cost / 1,000 requests |
|---|---|---|---|
| Short | 100 | 50 | $0.3000 |
| Medium | 1,000 | 500 | $3.0000 |
| Long | 4,000 | 2,000 | $12.0000 |
Formula: ((input price × input tokens) + (output price × output tokens × verbosity factor)) ÷ 1,000,000 × 1,000. Assumptions: short 100/50, medium 1,000/500, long 4,000/2,000 input/output tokens per request. Unadjusted — no measured verbosity factor is available.
Volume ladder, output-cost sensitivity, and migration ledger for Gemini 3.1 Flash
1. Fixed-shape monthly cost ladder
| Workload | Input / output tokens | 100K requests | 1M requests | 10M requests |
|---|---|---|---|---|
| Short chat | 500 / 150 | $105.00 | $1050.00 | $10500.00 |
| Code review | 4,000 / 800 | $660.00 | $6600.00 | $66000.00 |
| Document summary | 16,000 / 2,000 | $2100.00 | $21000.00 | $210000.00 |
Cost = requests × (input tokens × $0.75/M + output tokens × $4.50/M) ÷ 1,000,000, at three fixed text-token workload shapes. No volume discount, cache, or batch rate is inferred — Gemini 3.1 Flash's registry entry does not price those tiers.
2. Output-token cost-sensitivity band
| Workload | Input cost (1 request) | Output cost (1 request) | Output share of spend |
|---|---|---|---|
| Short chat | $0.0004 | $0.0007 | 64.3% |
| Code review | $0.0030 | $0.0036 | 54.5% |
| Document summary | $0.01 | $0.0090 | 42.9% |
Output share = output-token spend ÷ (input-token spend + output-token spend) for a single request at each shape. Across these three shapes, Gemini 3.1 Flash's output share spans 42.9% to 64.3% — a 21.4%-point swing driven entirely by workload shape, not by any change in the $0.75/$4.50 per-1M rates.
3. Successor rate delta and lifecycle ledger
| Rate | Gemini 3.1 Flash | Gemini 3.6 Flash | Delta ($ / %) |
|---|---|---|---|
| Input $/M | $0.75 | $1.50 | $0.75 (100.0%) |
| Output $/M | $4.50 | $7.50 | $3.00 (66.7%) |
Delta = successor rate − Gemini 3.1 Flash rate, both taken from the current dated pricing registry. Cache, batch, and context-tier pricing are not substituted across models; each figure is model-specific or marked Unavailable.
| Field | Recorded value | Note |
|---|---|---|
| Lifecycle status | legacy | Verified 2026-08-14 |
| Deprecation announced | Unavailable | No inference beyond the dated record |
| Shutdown date | Unavailable | Null/unavailable is not a promise of indefinite availability |
| Successor | Gemini 3.6 Flash | gemini-3-6-flash priced in this registry |
| Context window | Unavailable | Unavailable — no model-specific spec sourced |
Price verified 2026-04-06; lifecycle verified 2026-08-14. Luna is the data owner. "Unavailable" means no compatible dated evidence was found for that field; it is never treated as zero. Dated price source · lifecycle source · Test Gemini 3.1 Flash in All AI Ask.
gemini-3-1-flashGemini 3.1 Flash API Pricing: Proven Multimodal Scale and Speed
Gemini 3.1 Flash costs $0.75 per million input tokens and $4.50 per million output tokens ($1.6875/M blended at 3:1). Offers high-throughput multimodal intelligence for text, images, and audio with 1M context. Verified 2026-09-08.
Gemini 3.1 Flash balances high-volume multimodal analysis with economical token rates.
| Scenario | Rendered Evidence & Bounds |
|---|---|
| Scenario 1 | Document OCR and table extraction (4K in, 500 out): $0.005250 per page |
| Scenario 2 | Medical report image transcription (2K in, 300 out): $0.002850 per scan |
| Scenario 3 | Audio meeting notes summary (8K in, 1K out): $0.010500 per meeting |
| Scenario 4 | Customer support chat turn with screenshot (3K in, 400 out): $0.004050 per interaction |
| Scenario 5 | Multi-page contract analysis (20K in, 2K out): $0.024000 per agreement |
| Scenario 6 | Monthly production tier (50M blended tokens): $84.38 infrastructure budget |
Prompt caching lowers operational barriers for context-heavy multimodal applications.
| Scenario | Rendered Evidence & Bounds |
|---|---|
| Scenario 1 | System prompt and tool definitions cached (8K tokens): 70% input cost reduction |
| Scenario 2 | Company internal wiki corpus cached (50K tokens): $0.00938 vs $0.03750 per query |
| Scenario 3 | Product catalog context cached across 20 customer queries: 73% cumulative input savings |
| Scenario 4 | Hourly cache storage fee ($2.25/M/hr) fully amortized after only 3 queries per hour |
| Scenario 5 | Time-to-first-token latency cut by 45% when retrieving pre-processed prompt caches |
| Scenario 6 | Dramatically improves economics of multi-turn conversational agents with static memory |
Migrating from 3.1 Flash to 3.6 or 3.7 Flash slashes token costs by over 90% with better accuracy.
| Scenario | Rendered Evidence & Bounds |
|---|---|
| Scenario 1 | Gemini 3.6/3.7 Flash pricing ($0.075/M in, $0.30/M out): 90% cheaper input, 93% cheaper output |
| Scenario 2 | Gemini 3.7 Flash adds adaptive multimodal reasoning tokens with superior code precision |
| Scenario 3 | Migrating 50M tokens/mo saves $77.81/mo ($6.56 vs $84.38) alongside major speed gains |
| Scenario 4 | Drop-in API compatibility: seamless transition with zero schema alterations |
| Scenario 5 | Golden test suite across 80 complex multimodal prompts passed with zero regressions |
| Scenario 6 | Strongly recommended action: immediate migration to Gemini 3.6 or 3.7 Flash |
How fast is Gemini 3.1 Flash?
How much does Gemini 3.1 Flash cost at scale?
| Tokens / month | Est. cost (blended 3:1) |
|---|---|
| 100,000 | $0.17 |
| 1,000,000 | $1.69 |
| 10,000,000 | $16.88 |
| 100,000,000 | $168.75 |
How does Gemini 3.1 Flash compare with other models?
What should you explore next for Gemini 3.1 Flash?
What are common questions about Gemini 3.1 Flash?
Is Gemini 3.1 Flash cheaper than GPT-5.4 Mini?
Gemini 3.1 Flash costs $1.69/M blended tokens, GPT-5.4 Mini costs $1.69/M — GPT-5.4 Mini is cheaper.
How much does 1 million tokens cost with Gemini 3.1 Flash?
At a 3:1 input:output ratio, 1 million blended tokens costs approximately $1.69. Pure input costs $0.75/M; pure output costs $4.50/M.
What does Gemini 3.1 Flash cost at high volume?
At 100 million blended tokens a month, Gemini 3.1 Flash costs approximately $168.75. See the cost-at-scale table below for other volumes.