Conversion GemsConversion Gems

AI coding tools

SDKs, inference APIs, local runners, vector databases, observability and fine-tuning libraries. Many are free or open source, so compare the usage unit you pay for.

Scored by the Conversion Gems editorial team · reviewed June 2026 85 with a free plan · 52 with a free trial · median listed price $25/mo
86%of the 99 AI development tools we review offer a free plan.
Based on 99 tools in our database, reviewed June 2026.
99 tools
DetailsPricingFree planFree trialBest forReview
GitHub8.8 / 10Freemium$4/moper seatYesYesDevelopers and teams hosting code with GitReview GitHub
Vercel AI SDK8.7 / 10FreeFreeYes—TypeScript developersReview Vercel AI SDK
Vercel AI8.6 / 10FreeFreeYes—TypeScript/Next.js developers building AI-powered web appsReview Vercel AI
Ollama8.5 / 10Free$20/moYes—Developers running open LLMs locally for dev and prototypingReview Ollama
Openrouter8.5 / 10Usage-based$29/mo——Developers wanting one API for many modelsReview Openrouter
Langfuse8.4 / 10Freemium$29/moYes—AI teams wanting OSS observability with cloud optionReview Langfuse
Axolotl8.3 / 10FreeFreeYesYesML engineers fine-tuning open-weight LLMs (Llama, Mistral, Gemma, etc.)Review Axolotl
PEFT8.3 / 10FreeFreeYes—ML engineers fine-tuning open LLMs or diffusion models on consumer GPUsReview PEFT
Pgvector8.3 / 10FreeFreeYes—Developers who already run Postgres and want vector searchReview Pgvector
Pinecone8.3 / 10Freemium$20/moYesYesRAG pipelines and LLM-powered semantic search at scaleReview Pinecone
Ragas8.3 / 10FreeFreeYes—RAG pipeline developers needing automated quality metricsReview Ragas
Together8.3 / 10Usage-based$19/mo——Startups running open-source LLMs cheaper than OpenAIReview Together
Fireworks8.2 / 10Usage-basedUsage-basedpay as you go—YesAI engineers needing fast, scalable inference for open-source LLMs like Llama and MixtralReview Fireworks
Groqcloud8.2 / 10Freemium~$0.05approximateYesYesReal-time AI apps needing sub-100ms first-token latencyReview Groqcloud
Portkey8.2 / 10Freemium$49/moYesYesEngineering teams shipping production LLM features needing multi-provider fallbacks and cost trackingReview Portkey
Supabase8.2 / 10Freemium$25/moYesYesFull-stack developers building production SaaS appsReview Supabase
Weaviate8.2 / 10Freemium$45/moYesYesSemantic search and RAG pipelines in productionReview Weaviate
Bentoml8.1 / 10Freemium~$0.14approximateYesYesML engineers packaging and deploying inference services to productionReview Bentoml
Dspy8.1 / 10FreeFreeYes—ML engineers building systematic, reproducible LLM pipelinesReview Dspy
Litellm8.1 / 10Freemium$250/moYesYesPlatform teams giving many developers governed LLM accessReview Litellm
Phoenix Arize8.1 / 10Freemium$50/moYesYesLLM and RAG application developers who need span-level tracing out of the boxReview Phoenix Arize
Promptfoo8.1 / 10FreeCustomcontact salesYes—Developers benchmarking prompts, models and RAGReview Promptfoo
Qodo8.1 / 10Freemium$30/moper seatYesYesDevelopment teams seeking automated code reviewsReview Qodo
Chroma8.0 / 10FreemiumFreeYesYesAI engineers building RAG and LLM-powered searchReview Chroma
Cursor8.0 / 10Freemium$20/moYesYesProfessional developers who want agent-level AI in their daily coding workflowReview Cursor
FAL AI8.0 / 10Usage-basedUsage-basedpay as you go—YesAI startups building image or video generation productsReview FAL AI
Guidance8.0 / 10FreeFreeYes—Developers enforcing JSON/structured output from LLMsReview Guidance
llama.cpp8.0 / 10FreeFreeYes—Developers running LLMs locally and offlineReview llama.cpp
Milvus Cloud8.0 / 10FreemiumFreeYes—Developers building RAG/semantic-search applicationsReview Milvus Cloud
Qdrant8.0 / 10Freemium~$65/moapproximateYes—Developers building RAG and semantic-search applicationsReview Qdrant
Unstructured8.0 / 10Freemium~$0.03approximateYesYesAI engineers building RAG pipelines needing reliable document ingestionReview Unstructured
Weaviate Cloud8.0 / 10Freemium~$45/moapproximateYes—AI engineers building RAG pipelines and semantic search systemsReview Weaviate Cloud
Zilliz Cloud8.0 / 10Freemium~$70/moapproximateYesYesAI/ML teams building RAG and semantic search applicationsReview Zilliz Cloud
Apache Tika7.9 / 10FreeFreeYes—Developers building search indexing (Solr/Lucene) pipelinesReview Apache Tika
Codeium7.9 / 10Freemium$20/moYesYesSolo developers wanting zero-cost AI autocomplete across 70+ languagesReview Codeium
Continue7.9 / 10Freemium$20/moper seatYesYesDevelopers wanting open-source AI coding with full model flexibilityReview Continue
Helicone7.9 / 10Freemium$79/moYesYesStartups adding LLM logging with minimal code changesReview Helicone
mabl7.9 / 10CustomCustomcontact sales—YesQA engineersReview mabl
Milvus7.9 / 10FreeFreeYes—Engineering teams building RAG, semantic search or recommendationsReview Milvus
Windmill7.9 / 10Freemium$120/moYesYesEngineering teams building and maintaining internal tools and automationsReview Windmill
Zed7.9 / 10Freemium$10/moYesYesDevelopers seeking a fast, AI-integrated code editorReview Zed
Convex7.8 / 10Freemium$25/moYesYesTypeScript teams building real-time collaborative or multiplayer appsReview Convex
Modal7.8 / 10Freemium$30/moYesYesML engineers running batch inference or model fine-tuning jobsReview Modal
trigger.dev7.8 / 10Freemium$10/moYes—TypeScript teams building AI agents, LLM pipelines, or multi-step automationsReview trigger.dev
Trl7.8 / 10FreeFreeYes—ML engineers fine-tuning open LLMs with SFT, DPO or RLHFReview Trl
Ellipsis7.7 / 10FreemiumFreeYesYesDevelopment teams using GitHubReview Ellipsis
Kestra7.7 / 10FreemiumCustomcontact salesYes—Data and platform engineers wanting a modern, declarative orchestratorReview Kestra
Langsmith7.7 / 10Freemium$39/moper seatYesYesAI engineers building and debugging LLM pipelines in productionReview Langsmith
Llamaparse7.7 / 10Freemium$50/moYes—Developers building RAG over PDFs and Office docsReview Llamaparse
MindsDB7.7 / 10Freemium$9.95/moYesYesData teams that want AI agents querying live databases without custom ETLReview MindsDB
GitHub8.8 / 10
Freemium · $4/mo · Free trial

Developers and teams hosting code with Git

Free

TypeScript developers

Vercel AI8.6 / 10
Free

TypeScript/Next.js developers building AI-powered web apps

Ollama8.5 / 10
Free · $20/mo

Developers running open LLMs locally for dev and prototyping

Openrouter8.5 / 10
Usage-based · $29/mo

Developers wanting one API for many models

Langfuse8.4 / 10
Freemium · $29/mo

AI teams wanting OSS observability with cloud option

Axolotl8.3 / 10
Free · Free trial

ML engineers fine-tuning open-weight LLMs (Llama, Mistral, Gemma, etc.)

PEFT8.3 / 10
Free

ML engineers fine-tuning open LLMs or diffusion models on consumer GPUs

Pgvector8.3 / 10
Free

Developers who already run Postgres and want vector search

Pinecone8.3 / 10
Freemium · $20/mo · Free trial

RAG pipelines and LLM-powered semantic search at scale

Ragas8.3 / 10
Free

RAG pipeline developers needing automated quality metrics

Together8.3 / 10
Usage-based · $19/mo

Startups running open-source LLMs cheaper than OpenAI

Fireworks8.2 / 10
Usage-based · Free trial

AI engineers needing fast, scalable inference for open-source LLMs like Llama and Mixtral

Groqcloud8.2 / 10
Freemium · ~$0.05 · Free trial

Real-time AI apps needing sub-100ms first-token latency

Portkey8.2 / 10
Freemium · $49/mo · Free trial

Engineering teams shipping production LLM features needing multi-provider fallbacks and cost tracking

Supabase8.2 / 10
Freemium · $25/mo · Free trial

Full-stack developers building production SaaS apps

Weaviate8.2 / 10
Freemium · $45/mo · Free trial

Semantic search and RAG pipelines in production

Bentoml8.1 / 10
Freemium · ~$0.14 · Free trial

ML engineers packaging and deploying inference services to production

Dspy8.1 / 10
Free

ML engineers building systematic, reproducible LLM pipelines

Litellm8.1 / 10
Freemium · $250/mo · Free trial

Platform teams giving many developers governed LLM access

Freemium · $50/mo · Free trial

LLM and RAG application developers who need span-level tracing out of the box

Promptfoo8.1 / 10
Free · Custom

Developers benchmarking prompts, models and RAG

Qodo8.1 / 10
Freemium · $30/mo · Free trial

Development teams seeking automated code reviews

Chroma8.0 / 10
Freemium · Free · Free trial

AI engineers building RAG and LLM-powered search

Cursor8.0 / 10
Freemium · $20/mo · Free trial

Professional developers who want agent-level AI in their daily coding workflow

FAL AI8.0 / 10
Usage-based · Free trial

AI startups building image or video generation products

Guidance8.0 / 10
Free

Developers enforcing JSON/structured output from LLMs

llama.cpp8.0 / 10
Free

Developers running LLMs locally and offline

Milvus Cloud8.0 / 10
Freemium · Free

Developers building RAG/semantic-search applications

Qdrant8.0 / 10
Freemium · ~$65/mo

Developers building RAG and semantic-search applications

Unstructured8.0 / 10
Freemium · ~$0.03 · Free trial

AI engineers building RAG pipelines needing reliable document ingestion

Freemium · ~$45/mo

AI engineers building RAG pipelines and semantic search systems

Zilliz Cloud8.0 / 10
Freemium · ~$70/mo · Free trial

AI/ML teams building RAG and semantic search applications

Apache Tika7.9 / 10
Free

Developers building search indexing (Solr/Lucene) pipelines

Codeium7.9 / 10
Freemium · $20/mo · Free trial

Solo developers wanting zero-cost AI autocomplete across 70+ languages

Continue7.9 / 10
Freemium · $20/mo · Free trial

Developers wanting open-source AI coding with full model flexibility

Helicone7.9 / 10
Freemium · $79/mo · Free trial

Startups adding LLM logging with minimal code changes

mabl7.9 / 10
Custom · Free trial

QA engineers

Milvus7.9 / 10
Free

Engineering teams building RAG, semantic search or recommendations

Windmill7.9 / 10
Freemium · $120/mo · Free trial

Engineering teams building and maintaining internal tools and automations

Zed7.9 / 10
Freemium · $10/mo · Free trial

Developers seeking a fast, AI-integrated code editor

Convex7.8 / 10
Freemium · $25/mo · Free trial

TypeScript teams building real-time collaborative or multiplayer apps

Modal7.8 / 10
Freemium · $30/mo · Free trial

ML engineers running batch inference or model fine-tuning jobs

trigger.dev7.8 / 10
Freemium · $10/mo

TypeScript teams building AI agents, LLM pipelines, or multi-step automations

Trl7.8 / 10
Free

ML engineers fine-tuning open LLMs with SFT, DPO or RLHF

Ellipsis7.7 / 10
Freemium · Free · Free trial

Development teams using GitHub

Kestra7.7 / 10
Freemium · Custom

Data and platform engineers wanting a modern, declarative orchestrator

Langsmith7.7 / 10
Freemium · $39/mo · Free trial

AI engineers building and debugging LLM pipelines in production

Llamaparse7.7 / 10
Freemium · $50/mo

Developers building RAG over PDFs and Office docs

MindsDB7.7 / 10
Freemium · $9.95/mo · Free trial

Data teams that want AI agents querying live databases without custom ETL

Showing 50 of 99

About AI coding tools

AI development tools are the plumbing behind AI features: SDKs for calling models (Vercel AI SDK), gateways and inference APIs (Openrouter, Groqcloud, Fireworks), local model runners (Ollama), vector databases (Pinecone, Milvus Cloud), observability (Langfuse, Helicone) and fine-tuning libraries (Axolotl, Peft). It is among the most free-friendly corners of the AI section: 85 of the 99 have a free plan or open-source license, and many of the leaders score above 8 in our reviews. The bill usually comes from usage instead, whether tokens, requests, traces or GPU time, so compare the pricing unit rather than the plan name.

What to compare before you choose

The unit you pay for

Few tools here charge a simple subscription: most bill per token, request, trace or seat. GitHub, for example, charges per user ($4 Team, $21 Enterprise), while gateways and observability tools meter usage. Model spend on your expected volume, not the entry price.

Open source or managed

Open-source libraries cost nothing to license, but you supply the compute and the operations work, while managed services charge for hosting, scaling and support. Our reviews flag several open-source tools for teams without GPU access or the in-house skills to run their dependencies.

Language and stack fit

The Vercel AI SDK is TypeScript-first, and our reviews flag it and Vercel AI for Python-first ML workflows. Check your language, framework and deployment target before comparing features, because switching stacks later costs more than any subscription.

Questions about AI development software