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TensorZero and Portkey offer diverse features to streamline LLM engineering, including an LLM gateway, observability tools, and more. TensorZero is fully open-source and self-hosted, while Portkey offers an open-source gateway but otherwise requires a paid commercial (hosted) service. Additionally, TensorZero has more features around LLM optimization (e.g. advanced fine-tuning workflows and inference-time optimizations), whereas Portkey has a broader set of features around the UI (e.g. prompt playground).

Similarities

  • Unified Inference API. Both TensorZero and Portkey offer a unified inference API that allows you to access LLMs from most major model providers with a single integration, with support for structured outputs, batch inference, tool use, streaming, and more.
    → TensorZero Gateway Quickstart
  • Automatic Fallbacks, Retries, & Load Balancing for Higher Reliability. Both TensorZero and Portkey offer automatic fallbacks, retries, and load balancing features to increase reliability.
    → Retries & Fallbacks with TensorZero
  • Schemas, Templates. Both TensorZero and Portkey offer schema and template features to help you manage your LLM applications.
    → Prompt Templates & Schemas with TensorZero
  • Multimodal Inference. Both TensorZero and Portkey support multimodal inference.
    → Multimodal Inference with TensorZero

Key Differences

TensorZero

  • Open-Source Observability. TensorZero offers built-in open-source observability features, collecting inference and feedback data in your own database. Portkey also offers observability features, but they are limited to their commercial (hosted) offering.
  • Built-in Evaluations. TensorZero offers built-in evaluation functionality, including heuristics and LLM judges. Portkey doesn’t offer any evaluation features.
    → TensorZero Evaluations Overview
  • Open-Source Inference Caching. TensorZero offers open-source inference caching features, allowing you to cache requests to improve latency and reduce costs. Portkey also offers inference caching features, but they are limited to their commercial (hosted) offering.
    → Inference Caching with TensorZero
  • Open-Source Fine-Tuning Workflows. TensorZero offers open-source built-in fine-tuning workflows, allowing you to create custom models using your own data. Portkey also offers fine-tuning features, but they are limited to their enterprise ($$$) offering.
    → Fine-Tuning Recipes with TensorZero
  • Advanced Fine-Tuning Workflows. TensorZero offers advanced fine-tuning workflows, including the ability to curate datasets using feedback signals (e.g. production metrics) and the ability to use RLHF for reinforcement learning. Portkey doesn’t offer similar features.
    → Fine-Tuning Recipes with TensorZero
  • Automated Experimentation (A/B Testing). TensorZero offers advanced A/B testing features, including automated experimentation, to help your identify the best models and prompts for your use cases. Portkey only offers simple canary and A/B testing features.
    → Run adaptive A/B tests with TensorZero
  • Inference-Time Optimizations. TensorZero offers built-in inference-time optimizations (e.g. dynamic in-context learning), allowing you to optimize your inference performance. Portkey doesn’t offer any inference-time optimizations.
    → Inference-Time Optimizations with TensorZero
  • Programmatic & GitOps-Friendly Orchestration. TensorZero can be fully orchestrated programmatically in a GitOps-friendly way. Portkey can manage some of its features programmatically, but certain features depend on its external commercial hosted service.
  • Open-Source Access Control. Both TensorZero and Portkey offer access control features like TensorZero API keys. Portkey only offers them in the commercial (hosted) offering, whereas TensorZero’s solution is fully open-source.
    → Set up auth for TensorZero

Portkey

  • Prompt Playground. Portkey offers a prompt playground in its commercial (hosted) offering, allowing you to test your prompts and models in a graphical interface. TensorZero doesn’t offer a prompt playground today (coming soon!).
  • Guardrails. Portkey offers guardrails features, including integrations with third-party guardrails providers and the ability to use custom guardrails using webhooks. For now, TensorZero doesn’t offer built-in guardrails, and instead requires you to manage integrations yourself.
  • Managed Service. Portkey offers a paid managed (hosted) service in addition to the open-source version. TensorZero is fully open-source and self-hosted.