TypeScript

turbopuffer

Turbopuffer is the 'S3 for vectors'—it aggressively optimizes for cost by storing data in object storage rather than RAM. This makes it 10x cheaper than Pinecone for massive datasets (1B+ vectors), but you pay the penalty in cold-start latency (~400ms). Use it if you have terabytes of vectors and don't need sub-20ms latency on the first hit; avoid it if you need guaranteed low latency for every single query or require on-premise self-hosting.

Paid Python TypeScript Go

Qdrant

Vector Databases

Qdrant is the developer's choice for vector search—fast, written in Rust, and unopinionated about where you run it. It shines in hybrid search scenarios (dense + sparse) where precision matters. If you need raw performance and don't mind managing a few configs, use this. If you want a 'set it and forget it' serverless experience where you never think about nodes or RAM, look at Pinecone instead.

Python JavaScript TypeScript Rust Go+2

LanceDB

Vector Databases

LanceDB is the best choice if you need to store actual data (images, documents) alongside your vectors without managing a separate object store. Its disk-based architecture makes it incredibly cost-effective for large datasets, avoiding the massive RAM bills of in-memory alternatives. However, if you need sub-millisecond latency for high-frequency trading or real-time recommendation, sticking to a memory-native DB like Redis or Pinecone is safer.

Python JavaScript TypeScript Rust Go+1

Chroma

Vector Databases

Chroma is the 'SQLite of Vector Databases'—it is the default starting point for almost every Python developer building RAG apps due to its incredible ease of use. While it started as a local-only tool, it has matured into a serious contender with a serverless cloud offering and hybrid search capabilities. Use it for prototyping and mid-scale production apps where DX is paramount; look elsewhere if you need complex on-prem distributed clustering without managing it yourself.

Python JavaScript TypeScript Open Source

OpenAI TTS/Whisper

Speech & Voice

OpenAI's audio stack is the default choice for 80% of developers for a reason: Whisper is the gold standard for transcription accuracy, and the TTS API sounds better than almost anything else out of the box. However, it is not for power users who need granular control—TTS offers zero SSML support and only six voices, making it useless for character-heavy apps compared to ElevenLabs. Use Whisper for cheap, accurate transcription (managed or self-hosted), but look elsewhere if you need voice cloning or expressive direction.

Paid Python JavaScript TypeScript Go+2

Fish Audio

Speech & Voice

Fish Audio is the 'hacker's choice' for TTS—it offers a rare combination of a managed API and high-quality open-source models you can run yourself. Its latency is best-in-class for real-time agents, beating many big players, and the emotion tagging system is genuinely useful for creative apps. However, enterprise teams might find the documentation and SLA guarantees less mature than ElevenLabs. Use this if you need low-latency voice with personality; avoid if you need rock-solid, set-and-forget infrastructure for millions of boring transactional calls.

Freemium Python Go TypeScript Open Source

Cartesia

Speech & Voice

Cartesia is the speed demon of the voice API world, trading the heavy Transformer architecture of competitors for State Space Models (SSMs) to achieve blistering sub-100ms latency. It is the definitive choice for developers building real-time voice agents where 'awkward silence' is the enemy, offering a blazing fast TTS engine and an aggressively priced STT model ($0.13/hour). However, if you need offline, audiobook-grade narration where cost is king and latency is irrelevant, OpenAI or cheaper bulk providers might be a better fit.

Freemium Python JavaScript TypeScript

AssemblyAI

Speech & Voice

AssemblyAI is the 'Stripe for Speech'—it offers the best developer experience and accuracy for asynchronous transcription and understanding. Its 'LeMUR' feature is a game-changer, allowing you to run LLM prompts (summarize, extract action items) directly on audio streams without managing your own text pipeline. However, if you need Text-to-Speech generation or extreme sub-200ms latency for a frantic voice bot, look at Deepgram or ElevenLabs instead.

Python JavaScript TypeScript Go Java+1

Weights & Biases

Observability

Weights & Biases is the gold standard for ML engineers who want a single pane of glass for both model training and GenAI observability. Its 'Weave' toolkit brings rigorous evaluation and versioning to LLMs, making it ideal for teams actively fine-tuning models or building complex agents. However, for pure application developers just wrapping APIs without training needs, the feature set is overkill and data ingestion costs ($0.10/MB) can surprise you.

Freemium Python JavaScript TypeScript

LangSmith

Observability

If you are already deep into the LangChain ecosystem, LangSmith is a no-brainer—it visualizes complex agent chains better than anything else. However, for teams using raw OpenAI/Anthropic SDKs, the $39/seat + usage pricing feels steep compared to open-source alternatives like Langfuse. Use it if you need to debug 'Why did my agent do that?', but skip it if you just want simple logging for a chat bot.

Freemium Python JavaScript TypeScript Java

Langfuse

Observability

Langfuse is the developer's choice for open-source LLM observability, especially now that it's backed by ClickHouse (acquired Jan 2026). Its free tier is exceptionally generous (100k traces/mo), making it a no-brainer for startups and side projects. However, self-hosting the full stack now implies managing a ClickHouse instance, which adds ops overhead. Use it if you want full data sovereignty and deep tracing; avoid it if you just need a simple proxy logger without the infrastructure weight.

Python JavaScript TypeScript Open Source

Helicone

Observability

Helicone is the developer's choice for 'set it and forget it' LLM observability, winning on simplicity with its proxy-based architecture that requires zero SDK bloat. It excels at cost tracking and caching (saving you real money), making it ideal for startups and high-volume apps. However, teams needing deep, complex evaluation pipelines or who are allergic to proxy dependencies might prefer LangSmith or Braintrust.

Freemium Python JavaScript TypeScript Open Source

Tag

Explore by tags

All

API Available

C++

China-Based

Curl

Dart

Docker

Elixir

Enterprise

EU-Based

Fine-tuning

Free

Freemium

Function Calling

GDPR

Go

GraphQL

HIPAA

Java

JavaScript

JavaScript SDK

Kotlin

Kubernetes

LangChain

.NET

Node.js

Open Source

Paid

PHP

Python

Python SDK

React

React Native

REST API

Ruby

Rust

Self-Hosted

SOC2

Streaming

Swift

US-Based

Vision

turbopuffer

Qdrant

LanceDB

Chroma

OpenAI TTS/Whisper

Fish Audio

Cartesia

AssemblyAI

Weights & Biases

LangSmith

Langfuse

Helicone