API cost decision in 10 seconds

DeepSeek V3.1 vs Phi 4

Pick Phi 4 for lower cost; pick DeepSeek V3.1 only if the larger context window matters more.

Page updated: 2026-05-26T15:08:08Z Data confirmed: 2026-06-13T07:08:03Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Phi 4 for lower cost; pick DeepSeek V3.1 only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Phi 4 is estimated at $0.14 vs $0.6 for DeepSeek V3.1, saving $0.47 (77.7% lower).

Cost-first pickPhi 4

Context-first pickDeepSeek V3.1

Sample savings$0.4777.7%

10x traffic gap$4.7

DeepSeek V3.1 has more context, but Phi 4 saves $0.47 on the standard workload. At 10x that traffic, the same price gap is about $4.7. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Phi 4 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	DeepSeek V3.1	Phi 4
Input-heavy / RAG	5M input + 500K output	Phi 4	$1.45	$0.4
Balanced workload	1M input + 1M output	Phi 4	$1	$0.21
Output-heavy chatbot	1M input + 5M output	Phi 4	$4.16	$0.77

Cheaper input Phi 4 $0.21 vs $0.065 / 1M

Phi 4 is $0.14 cheaper per 1M input tokens (69% lower; 3.23x difference).

Cheaper output Phi 4 $0.79 vs $0.14 / 1M

Phi 4 is $0.65 cheaper per 1M output tokens (82.3% lower; 5.64x difference).

Larger context DeepSeek V3.1 163.84K vs 16.38K

DeepSeek V3.1 has 147.46K more context (10x larger).

Sample workload Phi 4 $0.6 vs $0.14

Phi 4 is $0.47 cheaper on the standard workload (77.7% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

DeepSeek V3.1 Calculating… Estimated API cost

Phi 4 Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Phi 4 has the lower input price; Phi 4 has the lower output price; DeepSeek V3.1 offers the larger context window. For the 1M input plus 500K output sample, Phi 4 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.6 for DeepSeek V3.1 and $0.14 for Phi 4.

Best Fit

Choose DeepSeek V3.1 when you care most about larger context window.

Choose Phi 4 when you care most about lower input-token price, and lower output-token price.

Decision Notes

On the standard 1M input plus 500K output workload, Phi 4 is estimated at $0.14 vs $0.6 for DeepSeek V3.1, saving $0.47 (77.7% lower).
Phi 4 is $0.47 cheaper on the standard workload (77.7% lower).
Phi 4 is $0.14 cheaper per 1M input tokens (69% lower; 3.23x difference).
Phi 4 is $0.65 cheaper per 1M output tokens (82.3% lower; 5.64x difference).
DeepSeek V3.1 has 147.46K more context (10x larger).

Head-to-Head Specs

Feature	DeepSeek V3.1 (DeepSeek)	Phi 4 (Microsoft)
Input Price prompt tokens per 1M	$0.21	$0.065
Completion Price per 1M tokens	$0.79	$0.14
Sample Workload Cost 1M input + 500K output	$0.6	$0.14
Context Window	163.84K	16.38K
Release Date	2025-08-21	2025-01-10
Popularity	#62	#139

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Phi 4	On the standard 1M input plus 500K output workload, Phi 4 is estimated at $0.14 vs $0.6 for DeepSeek V3.1, saving $0.47 (77.7% lower).
High-volume input processing	Phi 4	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Phi 4	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	DeepSeek V3.1	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

DeepSeek V4 Flash (free) can replace DeepSeek V3.1 when lower sample workload cost matters most: $0.
DeepSeek V4 Flash can replace DeepSeek V3.1 when lower sample workload cost matters most: $0.2.
DeepSeek V3.2 can replace DeepSeek V3.1 when lower sample workload cost matters most: $0.4.
R1 Distill Qwen 32B can replace DeepSeek V3.1 when lower sample workload cost matters most: $0.43.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.25 sample workload cost.
Owl Alpha offers 1.05M context with $0 sample workload cost.
DeepSeek V4 Flash offers 1.05M context with $0.2 sample workload cost.
MiMo-V2.5 offers 1.05M context with $0.28 sample workload cost.

Popular competitors

DeepSeek V4 Flash · DeepSeek · #1
Hy3 preview · Tencent · #2
MiMo-V2.5 · Xiaomi · #3
MiniMax M3 · MiniMax · #4

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

DeepSeek catalog

Review all tracked DeepSeek models before deciding whether this matchup is the right shortlist.

Open DeepSeek models

Microsoft catalog

Check other Microsoft models with comparable pricing, context, or release timing.

Open Microsoft models

DeepSeek V3.1

DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates. It extends the DeepSeek-V3 base with a two-phase long-context...

Phi 4

[Microsoft Research](/microsoft) Phi-4 is designed to perform well in complex reasoning tasks and can operate efficiently in situations with limited memory or where quick responses are needed. At 14 billion...