Compare 39+ free API development tools — Postman, Hoppscotch, Insomnia, Bruno, Mintlify, Swagger, RapidAPI, Nango, and more. Exact free tier limits. Catalogue dates July to November 2026.
The API development toolchain has fragmented into dozens of specialized free tools. Hoppscotch is a fully open-source (MIT) Postman alternative with REST, GraphQL, WebSocket, and MQTT support. Bruno stores API collections as files in Git — no cloud sync needed. Insomnia offers local-first API design and testing. And Mintlify generates beautiful API docs from OpenAPI specs with a free tier.
This page compares 41 free API development tools — from API testing clients and GraphQL platforms to mocking services, documentation tools, API marketplaces, and integration platforms. Cross-reference with our Postman alternatives guide for deeper Postman-specific comparisons.
Recent API Tool Pricing Changes
Postman: Postman's Free plan no longer includes cloud performance testing. Its pricing table gave Free "Performance testing (u... Source ↗
Postman: Free plan now single-user only. Team collaboration (shared workspaces, collection sharing) requires paid plan at $19/... Source ↗
Free OSS (MIT). API development ecosystem — REST, GraphQL, WebSocket, SSE, Socket.IO, MQTT testing. Real-time collaboration, environments, collections. Web, desktop, and CLIThe page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-25, so we cannot confirm these terms today.
API design, debugging, testing, and documentation platform — free tier: up to 4 users, unlimited projects, unlimited APIs, unlimited requests. API mocking included. 7-day change history
Free OSS (MIT). Git-based offline API client — REST, GraphQL, collections stored as files in your repo. No cloud, no accounts, no sync. Desktop app for Mac/Linux/Windows. The #1 open-source Postman alternative
Thunder Client is a lightweight REST API client. The Free plan is $0 per user/month, no credit card required. It includes the extension for VS Code, JetBrains, Cursor, Antigravity, Kiro and Devin; CLI and CI/CD; WebSocket, SSE and gRPC; MCP Server. Free limits include 3 collections, 50 requests per collection, 5 collection imports per month, 30 local collection runs per month per user. There is no limit for collection runs in CI/CD. Paid plans are billed annually: Starter is $3 per user/month, Business is $7, and Enterprise is $16. Local run limits are 250, 500, and unlimited respectively.
GraphQL federation and supergraph platform — forever free: up to 3 users, 1-day data retention, self-hosted router (60 req/min rate limit), community support. No credit card required
Proxy service for inspecting and debugging API calls. The free plan includes 10,000 requests per month.We could not read the page we cite for this offer when we last looked, on 2026-11-13, so we cannot confirm these terms today.
Open-source API client for designing and testing REST, GraphQL, gRPC, WebSocket, and SSE APIs. Local-first with Git sync and optional cloud storage. No account required for local testing. Desktop app for Mac/Linux/Windows. Free tier includes unlimited projects and collection runner
Post HTTP Requests Online. Popular Request Methods include GET, POST, PUT, DELETE, and HEAD. Supports Headers and Token Authentication. Includes a basic login system for saving your requests.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-29, so we cannot confirm these terms today.
Tools for designing OpenAPI specs, generating documentation, and building developer portals. From visual API designers to full documentation platforms.
API design and documentation platform (SmartBear) — no permanent free tier. Swagger's own pricing FAQ, read 2026-09-05: "You can get started with Swagger with a free trial, no credit card required, then choose the plan that best fits your usage and requirements." The same FAQ puts the free Swagger tools on the open-source side — Swagger Editor, Swagger UI and Swagger Codegen, run locally — and SwaggerHub among the commercial products. Plan prices are client-rendered and were not read.
Visually create Open API 3 definitions for free.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-10, so we cannot confirm these terms today.
rich text editing API — The Free Plan includes 1,000 editor loads per month and TinyMCE core editing features. A 14-day free trial of 21 + advanced features is also available.
Collaborative design API with instant API mock and generated documentation (Free for unlimited API blueprints and unlimited users with one admin account and hosted documentation).The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-13, so we cannot confirm these terms today.
Quickly auto-generate models/class/type/interface and serializers from JSON, schema, and GraphQL for working with data quickly & safely in any programming language. Convert JSON into gorgeous, typesafe code in any language.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-14, so we cannot confirm these terms today.
Mock API servers, fake data generators, and request inspection tools. Essential for frontend development, integration testing, and prototyping without a real backend.
No-code, cloud-based platform for mocking and debugging multi-protocol APIs (REST, SOAP, gRPC & GraphQL), providing instant servers with rules-based logic, CRUD & stateful mocking, proxying, and CORS management for faster integration and testing. The free plan includes 50 requests per day and provides a public dashboard/endpoint where anyone with the dashboard URL can view submitted requests and responses.
Create a fake REST API from a JSON object, and customize HTTP status codes, headers, and response bodies.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-10, so we cannot confirm these terms today.
Free public mock REST APIs: 200+ endpoints across 9 domains (e-commerce, finance, recruitment, education, healthcare, socials, markets, meteorology and aviation) with full CRUD, filtering and pagination. No signup and no API keys. Custom mock APIs are the paid Developer plan: $10/month after a 7-day free trial, with 50,000 API calls a month and 20 projects.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-22, so we cannot confirm these terms today.
Mockfly is a trusted development tool for API mocking and feature flag management. Quickly generate and control mock APIs with an intuitive interface. The free tier offers 500 requests per day.
Proxy your API, choose which endpoints to mock in the cloud and inspect traffic, for free. Speed up your development and integration tests.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-10, so we cannot confirm these terms today.
Create a free endpoint to which you can send HTTP requests. Any HTTP requests sent to that endpoint will be recorded with the associated payload and headers so you can observe recommendations from webhooks and other services.The page we cite for this offer does not name it when we last looked, on 2026-10-22, so we cannot confirm these terms today.
Mockaroo generates up to 1,000 rows of realistic test data for free, in CSV, JSON, SQL, and Excel formats. It also lets you design mock back-end APIs. Paid plans start at $60 a year.
Platforms offering curated collections of third-party APIs — from geolocation and email validation to product data and exchange rates. Most offer generous free tiers per API.
Suite of 15 REST APIs (IP geolocation, email validation, screenshots, exchange rates, phone validation, etc.) — free tier: 1,000 requests/month per API, 1 request/second rate limit. Non-commercial use only on free tierWhen we last read the page we cite for this offer, on 2026-11-01, we found the same terms as an earlier read we had declined to record, so we cannot confirm these terms today.
API marketplace hosting 90+ data APIs (exchangeratesapi, ipstack, mediastack, etc.). Most APIs include a free tier with 100-1,000 requests/month. Individual API pricing varies by providerThe page we cite for APILayer states in words that it is free, which confirms the price — the limits stated here come from our own record rather than from that page.
API marketplace and hub — free to sign up and browse. Individual APIs set own free tiers (typically 500-1K req/mo). Platform rate limits: 1,000 req/hr, 500K req/mo. No platform fee on free API tiersWe could not read the page we cite for this offer when we last looked, on 2026-11-13, so we cannot confirm these terms today.
Get instant access to over 120+ APIs for free, built with quality, consistency, and reliability in mind. The free plan covers up to 50 API Tokens per month. (Possibly taken down, 2025-06-25)When we last read the page we cite for this offer, on 2026-11-10, we found a change we could not reconcile with the terms we publish, so we cannot confirm these terms today.
Platforms for connecting APIs together, managing webhooks, monitoring API usage, and building integration pipelines. These handle the plumbing between your services.
Hook0 is an open-source Webhooks-as-a-service (WaaS) that makes it easy for online products to provide webhooks. Dispatch up to 100 events/day with seven days of history retention for free.
PDF generation API. The Free plan includes 50 documents a month, 20 requests per minute, 1 concurrent request, a 2 MB PDF file size limit, 1 template and 1 AI template generation, with no credit card required. Paid plans start with Basic at $19 a month for 2,000 documents.
Create secure RESTful APIs from CSV files. Upload a CSV file and instantly access the data via its API allowing faster application development. The free plan includes 2 APIs and 2,500 API calls per month. You don't need a credit card.
Treblle helps teams build, ship, and govern APIs. With advanced API log aggregation, observability, docs, and debugging. You get all features for free, but there is a limit of up to 250k requests per month on the free tier.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-10, so we cannot confirm these terms today.
The Amazon Selling Partner API (SP-API) is for building seller and vendor tools on Amazon. SP-API is free for sellers and third-party developers. Amazon announced a $1,400 annual fee for developers and per-call fees in late 2025, but delayed and then postponed them. In May 2026, Amazon said it "will not move forward with the SP-API usage and annual fees at this time."The page we cite for this offer does not name it when we last looked, on 2026-10-10, so we cannot confirm these terms today.
Product data management API for Google Merchant Center. Sunset on 2026-08-18. Its successor, Merchant API, has been generally available since July 2025. Free to use with a Google Merchant Center account. Provided product listing, inventory management, and order management endpoints. Developers must migrate to Merchant API before the sunset date.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-15, so we cannot confirm these terms today.
Free and open-source desktop app for creating local API mocks — dynamic responses, request logging, record/replay and OpenAPI import. Mockoon Pro adds team collaboration and deployed mock instances. It is self-hosted on the customer's own infrastructure. The Team plan costs €10 per license a month, billed €120 per license a year, with a minimum of 5 licenses. A 14-day free trial is available for companies with a verified work email.
Automatically generate RESTful API documentation with Swagger 2.0 for Go. Annotate your handler functions, run swag init, and get a Swagger UI endpoint; works with chi, gin, echo, fiber and net/http. Free and MIT-licensed, with optional sponsorship through Open Collective.The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-10-15, so we cannot confirm these terms today.
Hoppscotch and Bruno lead the open-source API client space — both MIT-licensed with no vendor lock-in. Postman remains the industry standard with the largest ecosystem. For GraphQL, Apollo GraphOS handles federation while Hasura generates instant APIs. Mintlify is the top choice for modern API docs. Catalogue dates July to November 2026.
Which Free API Tool Should I Use?
Need a free Postman alternative?
Hoppscotch — fully open-source (MIT) with REST, GraphQL, WebSocket, SSE, Socket.IO, and MQTT support. Self-hostable. See our Postman alternatives guide for a deeper comparison.
Want Git-native API collections?
Bruno — stores collections as files on your filesystem, version-controllable in Git. No cloud account needed. MIT licensed.
Need an all-in-one API design + test + docs platform?
Apidog — free for up to 4 users with unlimited APIs, combining API design, debugging, testing, mocking, and documentation in one tool.
Building beautiful API documentation?
Mintlify — free tier includes custom domain, web editor, and API playground. Stoplight for OpenAPI visual design. SwaggerHub for Swagger/OpenAPI hosting.
Need instant GraphQL APIs?
Hasura — generates a GraphQL API over any database instantly. Hasura DDN Free plan: unlimited API requests and unlimited concurrent users (1 supergraph developer, 15-min observability retention). Apollo GraphOS for GraphQL federation and supergraph management.
Need mock APIs for frontend development?
Beeceptor — no-code mock APIs for REST, SOAP, and GraphQL. MockAPI for quick REST mocking with custom data. mockaroo for realistic test data generation.
Looking for third-party data APIs?
RapidAPI — largest API marketplace with thousands of APIs. AbstractAPI for geolocation, email validation, and utility APIs. API Ninjas for 100+ free REST APIs.
Need to connect multiple APIs together?
Nango — integration infrastructure for 600+ APIs with unified auth and data syncing, 10 connections free. Treblle for API observability and governance.
Looking for more? Browse all API Development tools or search across all 1,498 tools in the AgentDeals index.
More Alternatives Guides
LocalStack CE Alternatives— In March 2026, LocalStack merged Community and Pro images, requiring an auth token for the latest image — compare 9 free open-source AWS emulators
Postman Alternatives— Postman killed free team collaboration March 1, 2026 — 5 free API testing alternatives
HCP Terraform Alternatives— HCP Terraform legacy free plan ended March 31, 2026; free tier now caps managed resources at 500 — free IaC alternatives compared
Freshping Alternatives— Freshping shut down March 6, 2026 — 13 free uptime monitoring alternatives
Heroku Alternatives— Heroku removed free tier Nov 2022, entered sustaining mode Feb 2026 — 8 free PaaS options
Firebase Alternatives— Firebase Studio is closing (no new workspaces since June 22, 2026; shutdown March 22, 2027) + Cloud Storage for Firebase now requires Blaze — 7 BaaS alternatives
GitHub Actions Alternatives— GitHub postponed its self-hosted runner fee, so self-hosted runners stay free — 10 free CI/CD alternatives compared
Best Free AI & ML Tools for Developers in 2026— 65+ AI/ML tools and their free tiers compared — LLM APIs, AI coding assistants, ML platforms, observability, and specialized AI services
Best Free LLM APIs in 2026— 25+ LLM API providers and their free tiers compared — proprietary model APIs, open-model inference platforms, and AI gateways with exact rate limits
The Complete Free Startup Stack for 2026— Complete free SaaS infrastructure stack — 10 categories with recommended picks, scaling guidance, and stability ratings
The Complete Free AI/ML Stack for 2026— Complete free AI/ML development stack — 10 categories with recommended picks, scaling guidance, and stability ratings
The Complete Free DevOps Stack for 2026— Complete free DevOps infrastructure stack — 10 categories with recommended picks, scaling guidance, and stability ratings
The Complete Free Frontend Stack for 2026— Complete free frontend/Jamstack development stack — 10 categories with recommended picks, scaling guidance, and stability ratings
The Complete Free Next.js Stack for 2026— Complete free Next.js full-stack infrastructure — 10 layers with recommended picks, growth cost analysis, and stability ratings
Google Developer Program 2026— Standalone Google Developer Program Premium no longer takes sign-ups — current plans, Cloud credits and free alternatives
Vercel vs Netlify Free Tier Comparison— Deep comparison of Vercel and Netlify free tiers — bandwidth, functions, builds, commercial use, and scaling costs
Railway vs Render Free Tier Comparison— Deep comparison of Railway and Render free tiers — usage-based vs fixed pricing, databases, sleep behavior, and scaling costs
Datadog vs New Relic Free Tier Comparison— Deep comparison of Datadog and New Relic free tiers — per-host vs per-GB pricing, APM, logs, synthetics, and scaling costs
Free Tier Risk Index— Predictive risk analysis for developer free tiers — grades dated and scored against what happened next, category heatmap, pattern analysis, counter-trends
Gemini API Pricing 2026— Gemini API billing guide — spend caps ($250-$100K+/mo), prepaid billing, 3.1 Pro paid-only, free tier changes, 8-provider comparison
Free Tier Tracker 2026— A list of developer tool free tiers that were removed or cut in 2026, grouped by quarter, with dates and what changed.
Startup Credits Comparison 2026— The definitive startup credits comparison — 16 programs across cloud infrastructure, fintech, and developer tools with eligibility requirements, vesting schedules, and stacking strategies
AI Coding Tools Pricing Comparison 2026— The definitive AI coding tools comparison — 17 tools across IDE, CLI, cloud agent, and app builder categories with free tier analysis and cost breakdowns
CI/CD Tools Pricing Comparison 2026— The definitive CI/CD pricing comparison — 17+ tools across general, cloud-native, mobile, and self-hosted categories with free tier analysis and cost breakdowns
Database Pricing Comparison 2026— The definitive database pricing comparison — 25+ services across managed Postgres, serverless/edge, document/NoSQL, cloud provider, and specialized categories with free tier analysis and cost breakdowns
Vector Database Pricing Comparison 2026— The definitive vector database pricing comparison — 11 services across dedicated cloud, open-source, pgvector, embedded, and serverless categories with free tier analysis for RAG/AI
Cloud Hosting & PaaS Pricing Comparison 2026— The definitive cloud hosting pricing comparison — 15 platforms across PaaS, edge/serverless, full-featured, and static categories with free tier analysis, pricing gotchas, and Railway referral
LLM API Free Tiers & Free Credits 2026— Which LLM APIs have a genuinely free tier or free credits — frontier labs, inference providers, open-source hosts, and specialized services with free tier analysis and token cost breakdowns
AWS Free Tier 2026— AWS Free plan: up to $200 in credits over 6 months, 30+ always-free services, short-term trials, hidden costs, cheaper alternatives.
GCP Free Tier Complete Guide 2026— Complete GCP free tier guide — 20+ always-free products, $300 trial, hidden costs, and comparison with AWS and Azure
Azure Free Tier 2026— Azure free tier guide — 65+ always-free services, $200 trial, Cosmos DB lifetime free tier, and comparison with AWS and GCP
Testing & QA Tools Free Tier Comparison 2026— Side-by-side comparison of 15+ testing tool free tiers — E2E, visual regression, load testing, API testing, local dev, and the testing cost trap at scale
API Development Tools Free Tier Comparison 2026— Side-by-side comparison of 12+ API development tool free tiers — users, collections, requests, mock servers, local-first vs cloud, and the API tool migration trap
Hosting & PaaS Free Tier Comparison 2026— Side-by-side comparison of 12+ hosting free tiers — bandwidth, compute, build minutes, cold starts, commercial use restrictions, and the hosting cost trap at scale
Developer Security Tools Free Tier Comparison 2026— Side-by-side comparison of 20+ developer security tool free tiers — SAST, SCA, DAST, secrets detection, container security, and the DevSecOps cost trap at scale
Firebase Studio Shutdown Guide— Firebase Studio shuts down March 22, 2027 — free cloud IDE alternatives with compute, storage, and collaboration limits compared
Developer Tool Shutdown Tracker 2026— Living tracker of developer tool shutdowns, API sunsets, and deprecation deadlines in 2026 — with migration paths and alternatives
Forming a US Company in 2026: Costs and Changes— Firstbase Start costs $99 under an offer plus a required $299-a-year agent. Stripe pays the $500 Atlas fee back for a $5,000 Treasury deposit. Delaware's LLC tax is $400.