DeepSeek R1 vs GPT 4.5 preview
DeepSeek R1 (Azure AI Foundry, 128,000-token context) versus GPT 4.5 preview (Azure OpenAI, 128,000-token context). DeepSeek R1 is cheaper by 97% on a blended token mix. DeepSeek R1 uniquely supports native reasoning mode. GPT 4.5 preview uniquely supports function calling and parallel tool calls. Across 4 public benchmarks we tracked, DeepSeek R1 wins 3 and GPT 4.5 preview wins 1. Use the live calculator below to plug your real usage shape into both, then route the winner via Agent Command Center for shadow A/B without code changes.
Bottom line — DeepSeek R1 vs GPT 4.5 preview
DeepSeek R1 and GPT 4.5 preview target overlapping workloads but differ sharply on economics. DeepSeek R1 runs roughly 97% cheaper on a blended input-plus-output token mix, which translates to approximately $307,710 per month at mid-market volume (100K requests/day). The gap compounds at enterprise scale, making the cost axis the first filter most teams apply when deciding between these two models.
On capability surface area, the models diverge: DeepSeek R1 supports native reasoning mode where the other does not; GPT 4.5 preview supports function calling where the other does not; GPT 4.5 preview supports parallel tool calls where the other does not. These differences are binary — either your workload needs the capability or it does not. Check whether any critical path in your agent pipeline depends on a capability only one model provides before committing to a migration.
Across 4 public benchmarks, DeepSeek R1 leads on 3 and GPT 4.5 preview leads on 1. The widest gap is on arena-elo, where GPT 4.5 preview scores 83.0 points higher. Benchmarks are noisy and task-dependent — a model that leads on arena-elo may trail on code generation. The safest approach is to run both models on your own golden set before treating any benchmark as decisive.
For teams evaluating both models, the recommended path is a shadow A/B test: route production traffic through an OpenAI-compatible gateway, mirror a percentage to the candidate model, score both responses with an automated evaluator (faithfulness, tool-call correctness, latency), and compare cohort-level metrics over two weeks. Future AGI Agent Command Center supports this pattern with a single `base_url` change and built-in evaluators from the ai-evaluation SDK.
Live workload comparison
Same workload run through both models. The cheaper one is highlighted.
strategy: cost-optimized
primary:
model: deepseek-r1
provider: azure-ai-foundry
fallback:
model: gpt-4-5-preview
provider: azure-openai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| DeepSeek R1 | GPT 4.5 preview | |
|---|---|---|
| Input price | $1.35/M | $75.00/M |
| Output price | $5.40/M | $150/M |
| Context window | 128,000 | 128,000 |
| Max output | 8,192 | 16,384 |
| Function calling | — | ✓ |
| Vision | — | ✓ |
| Audio input | — | — |
| Reasoning | ✓ | — |
| Prompt caching | — | ✓ |
| Structured output | — | ✓ |
| Pricing verified | Jun 2, 2026 | Jun 2, 2026 |
Benchmark comparison
Side-by-side public benchmark scores. Greener bar = winner.
Cost at scale: monthly spend at three usage volumes
Estimated monthly cost assuming 1,000 input + 200 output tokens per request — a realistic chat-agent shape. Adjust your own usage in the calculator at the top of this page for an exact number.
| Scale | DeepSeek R1 | GPT 4.5 preview | Delta |
|---|---|---|---|
| Startup 10K requests/day | $729 /mo | $31,500 /mo | $30,771/mo |
| Mid-market 100K requests/day | $7,290 /mo | $315,000 /mo | $307,710/mo |
| Enterprise 1M requests/day | $72,900 /mo | $3,150,000 /mo | $3,077,100/mo |
At enterprise scale (1M requests/day), a difference of even ~10% in unit price compounds into thousands of dollars per month. Cached input pricing and batch tiers can shift this further — both are surfaced on each model's own page.
When to choose which
Picked from the data above — not vendor marketing. Match the rules to your workload, not the other way around.
You're cost-sensitive at scale — DeepSeek R1 runs ~97% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume.
Your inputs include screenshots, diagrams, or product photos — GPT 4.5 preview accepts image input natively, the other doesn't.
Your tasks involve multi-step planning or math-heavy reasoning — DeepSeek R1 ships a native reasoning mode that explicitly thinks before responding, the other doesn't.
You re-send the same large system prompt across requests — GPT 4.5 preview supports prompt caching, cutting input cost on repeat hits.
Your agent calls tools or APIs — GPT 4.5 preview supports function calling natively, the other model needs a parser shim.
On arena-elo, GPT 4.5 preview scores 83.0 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.
Capability diff — what you gain and lose on the swap
A specific list of what each model has that the other doesn't. If your workload depends on a row in Only DeepSeek R1, switching to GPT 4.5 preview means re-architecting that path (and vice versa).
- • Native reasoning mode
- • Function calling
- • Parallel tool calls
- • Vision input
- • Structured output (JSON schema)
- • Prompt caching
Capabilities both share (1)
- ✓ Streaming
Benchmark winners — by the numbers
For each public benchmark that has scores for both models, the higher score and the size of the gap. Benchmarks are noisy — treat anything under a 2-point delta as effectively tied.
| Benchmark | DeepSeek R1 | GPT 4.5 preview | Winner | Δ |
|---|---|---|---|---|
| aime-2024 | 79.8 | 36.7 | DeepSeek R1 | +43.1 |
| arena-elo | 1361.0 | 1444.0 | GPT 4.5 preview | +83.0 |
| mmlu | 90.8 | 85.1 | DeepSeek R1 | +5.7 |
| swe-bench-verified | 49.2 | 38.0 | DeepSeek R1 | +11.2 |
Migration considerations
Concrete differences to wire through your stack before you flip traffic from one to the other.
- Max output tokens differ: 8,192 on DeepSeek R1 vs 16,384 on GPT 4.5 preview. Long-form generation tasks may truncate differently — adjust streaming UI and chunking accordingly.
- DeepSeek R1 has capabilities GPT 4.5 preview lacks: Native reasoning mode. Switching to GPT 4.5 preview means re-architecting any flow that depends on these.
- GPT 4.5 preview has capabilities DeepSeek R1 lacks: Function calling, Parallel tool calls, Vision input, Structured output (JSON schema), Prompt caching. Worth wiring through the agent design before commit.
- Provider changes from Azure AI Foundry to Azure OpenAI. API authentication, rate-limit policy, regional availability, and billing all shift. Most teams route through an OpenAI-compatible gateway (e.g., Future AGI Agent Command Center) so the swap is a single `base_url` change instead of an SDK rewrite.
How to A/B test DeepSeek R1 vs GPT 4.5 preview in production
If you're stuck between the two, run them side-by-side on real traffic. Four steps the Future AGI team uses internally:
- 1. Point your existing OpenAI SDK at
https://gateway.futureagi.com/v1. No code change beyondbase_urland a virtual key. - 2. Mark DeepSeek R1 primary, mirror 20% of traffic to GPT 4.5 preview in shadow mode. Both responses are logged; only the primary is served to users.
- 3. Score every shadow response with an evaluator — faithfulness, tool-call correctness, response latency, cost. Built-in evaluators in ai-evaluation cover the common axes.
- 4. Compare cohort-level metrics after two weeks. Switch primary when the candidate wins on what matters to your workload — and stays within your latency budget.
Full walkthrough on the Agent Command Center page.
FAQ — DeepSeek R1 vs GPT 4.5 preview
Which is cheaper, DeepSeek R1 or GPT 4.5 preview? ▾
DeepSeek R1 is cheaper by roughly 97% on a blended input + output token mix. Input prices are $1.35/M for DeepSeek R1 versus $75.00/M for GPT 4.5 preview; output prices are $5.40/M versus $150/M. The exact savings depend on your input:output ratio — use the live calculator above to plug in your own request shape.
What is the context window of DeepSeek R1 versus GPT 4.5 preview? ▾
DeepSeek R1 supports up to 128,000 tokens of context. GPT 4.5 preview supports up to 128,000 tokens. GPT 4.5 preview has the larger window by a factor of 1.0x, which matters for long-document RAG, multi-turn agent sessions, and tasks that need to keep an entire codebase in working memory.
Do DeepSeek R1 and GPT 4.5 preview both support tool calling? ▾
Only GPT 4.5 preview supports native function calling. The other model can still be made to call tools through a structured-output workaround, but the reliability of that pattern is lower than native support.
Can DeepSeek R1 and GPT 4.5 preview process images? ▾
GPT 4.5 preview accepts native image input. DeepSeek R1 does not — you would need to route image-heavy workloads through GPT 4.5 preview or add a separate vision model in front of DeepSeek R1.
Which model supports prompt caching for cost reduction? ▾
GPT 4.5 preview supports prompt caching; the other does not. If your agent has a stable system prompt + retrieval context block that repeats across requests, GPT 4.5 preview gives you a 50–90% discount on those repeated input tokens at the provider level.
When should I choose DeepSeek R1 over GPT 4.5 preview? ▾
You're cost-sensitive at scale — DeepSeek R1 runs ~97% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume. Your tasks involve multi-step planning or math-heavy reasoning — DeepSeek R1 ships a native reasoning mode that explicitly thinks before responding, the other doesn't.
When should I choose GPT 4.5 preview over DeepSeek R1? ▾
Your inputs include screenshots, diagrams, or product photos — GPT 4.5 preview accepts image input natively, the other doesn't. You re-send the same large system prompt across requests — GPT 4.5 preview supports prompt caching, cutting input cost on repeat hits. Your agent calls tools or APIs — GPT 4.5 preview supports function calling natively, the other model needs a parser shim. On arena-elo, GPT 4.5 preview scores 83.0 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.
How do I A/B test DeepSeek R1 against GPT 4.5 preview in production? ▾
Route both through an OpenAI-compatible gateway like Future AGI Agent Command Center with shadow mode enabled. Send 100% of traffic to your primary model, mirror 10–20% to the candidate, score every response with an evaluator (faithfulness, tool-call correctness, response time), and compare cohort-level metrics for two weeks. Switch when the candidate wins on the metrics that matter to your workload and stays within your latency budget.