Phi-3 Small 128K
Phi-3 Small 128K is worth evaluating for coding, long context, and classification when its provider route and context window match the workload.
Use it for
- Teams evaluating coding, long context, and classification
- Workloads that can use a 128k context window
- Buyers comparing 2 tracked provider routes
Do not use it for
- Vision or document-understanding workloads
- Strict JSON or tool-calling flows
Advancing the state-of-the-art in AI and computing.
Cheapest of 2 routes · Microsoft Foundry
About
Phi-3 Small 128K is Microsoft Research's Phi-3 model. It offers a 128K-token context window with weights openly available for self-hosting and scores 51.9 on GPQA.
Phi-3 Small 128K is an open-source model in the Phi-3 family. The structured metadata tracks a 128k-token context window. This page tracks provider routes through Microsoft Foundry and NVIDIA NIM, with the cheapest tracked route listed at $0.35 input and $1.05 output per 1M tokens. Headline tracked benchmarks include Google-Proof Q&A 51.9, HellaSwag 90.8, and HumanEval 73.8.
Top use-case fit: coding, agents, and build tasks
Coding
Q/$ C1 relevant benchmark in the decision map.
Long context
Included by capability and metadata signals in the decision map.
Classification
Q/$ C2 relevant benchmarks in the decision map.
Provider price ladder
Compare all 2Compare API pricing across 2 providers for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Route |
|---|---|---|---|
| Microsoft Foundry | $0.350 | $1.05 | ServerlessProvisioned |
| NVIDIA NIM | - | - | ProvisionedPartial |
Available via routers & gateways(6)
LiteLLM
GatewayOpen-source Python SDK and proxy server that unifies 100+ LLM APIs behind a single OpenAI-compatible interface, with load balancing, cost tracking, and configurable failover.
Portkey
GatewayProduction AI gateway routing to 1,600+ LLMs with failover, load balancing, semantic caching, and guardrails; Apache 2.0 core is fully self-hostable with the complete feature set.
Azure AI Foundry Model Router
RouterMicrosoft Azure AI Foundry's native model router that uses a trained ML model to route each prompt in real time to the optimal Azure-hosted model, with Balanced/Cost/Quality mode selection and automatic failover.
Helicone
GatewayObservability-first AI gateway with routing, caching, rate limiting, and request tracing; Apache 2.0 open-source core with a managed hosted tier for logging and analytics.
Kong AI Gateway
GatewayMulti-LLM AI gateway built on Kong Gateway 3.x, adding semantic routing, load balancing, guardrails, and MCP traffic analytics as plugins over Kong's existing API management platform.
NVIDIA LLM Router Blueprint
RouterNVIDIA's open-source AI blueprint for LLM routing that selects the optimal model per prompt via intent classification or neural auto-routing; being deprecated 2026-06-20.
Capabilities
No model capability flags are currently sourced.
Benchmark peer barsfor Coding
Benchmark scores(4)
| Benchmark | Score | Version | Source |
|---|---|---|---|
| Google-Proof Q&A | 51.9 | diamond | https://arxiv.org/abs/2404.14219 |
| HellaSwag | 90.8 | 10-shot | https://arxiv.org/abs/2404.14219 |
| HumanEval | 73.8 | pass@1 | https://arxiv.org/abs/2404.14219 |
| Massive Multitask Language Understanding | 78.1 | 5-shot | https://arxiv.org/abs/2404.14219 |
Migration checks
No linked migration route is available for this model yet.
Rankings & picks(1)
Frequently asked questions
What is the context window of Phi-3 Small 128K?
Phi-3 Small 128K has a context window of 128k tokens.
How much does Phi-3 Small 128K cost?
Phi-3 Small 128K is available at $0.35/1M input tokens through Microsoft Foundry.
When was Phi-3 Small 128K released?
Phi-3 Small 128K was released on 2024-05-21.
Which providers offer Phi-3 Small 128K?
Phi-3 Small 128K is available from 2 providers: Microsoft Foundry, NVIDIA NIM.
What benchmarks has Phi-3 Small 128K been tested on?
Phi-3 Small 128K has been evaluated on 4 benchmarks, including Google-Proof Q&A, HellaSwag, HumanEval, Massive Multitask Language Understanding.
Advancing the state-of-the-art in AI and computing.
Cheapest of 2 routes · Microsoft Foundry