Running an API does not have to cost money. Whether you are building a side project, an open-source tool, or just learning backend development, there are several platforms that offer genuinely useful free tiers. We have used most of them at various points while building MC Heads, and this guide covers the real trade-offs — not just the marketing pages.
The Free Tier Landscape in 2026
The free tier ecosystem has matured significantly over the past few years. The major players are Vercel, Railway, Fly.io, and Cloudflare Workers. Each has different strengths, and the right choice depends on what kind of API you are building.
Here is the quick summary before we dive deep:
- Vercel: Best for Next.js and serverless functions. Generous free tier but with cold start latency.
- Railway: Best for traditional server applications. Simple deployment but limited free hours.
- Fly.io: Best for always-on services with global distribution. Generous compute but requires more configuration.
- Cloudflare Workers: Best for lightweight, edge-deployed APIs. Extremely fast but with runtime limitations.
Vercel: The Serverless Default
Vercel's free tier is hard to beat for serverless APIs, especially if you are already using Next.js. You get 100GB of bandwidth per month, serverless function invocations with up to 10 seconds of execution time, and automatic HTTPS and global CDN distribution.
The good: Deployment is dead simple — push to GitHub and your API is live. The global CDN means your responses are fast everywhere. The integration with Next.js API routes and server actions is seamless.
The bad: Cold starts are real. If your function has not been invoked recently, the first request can take 1 to 3 seconds while the runtime spins up. This is acceptable for most use cases but painful for latency-sensitive applications. The free tier also limits you to a 10-second execution timeout, which rules out long-running operations.
Cost breakdown for the free tier:
- Serverless function executions: 100,000 per month
- Bandwidth: 100GB per month
- Build minutes: 6,000 per month
- Concurrent builds: 1
When it breaks free: If you exceed 100,000 function invocations or 100GB of bandwidth, you need the Pro plan at $20/month. In practice, a moderately popular API can hit the invocation limit before the bandwidth limit.
Best for: APIs that can tolerate cold starts, Next.js projects, webhook handlers, and APIs with bursty rather than constant traffic patterns.
Railway: Traditional Servers Made Simple
Railway is the closest thing to "just give me a server" in the free tier world. You deploy a Docker container or a supported runtime (Node.js, Python, Go, Rust, etc.), and Railway runs it on actual compute infrastructure.
The good: No cold starts — your application stays running. You get a real server with persistent connections, background jobs, and WebSocket support. The deployment experience is smooth: connect your GitHub repo, and Railway detects your framework and builds automatically.
The bad: The free tier gives you $5 of credit per month, which translates to roughly 500 hours of a small instance. If your application runs 24/7, that is about 21 days — not quite a full month. You need to be strategic about when your application sleeps or accept that it will go down near the end of the month.
Cost breakdown for the free tier:
- $5 credit per month (no rollover)
- 512MB RAM per service
- Shared CPU
- 1GB disk per service
- No custom domains (use Railway's subdomain)
When it breaks free: The $5 credit gets consumed by uptime, memory usage, and network egress. A Node.js API running 24/7 with moderate traffic will typically exhaust the credit in 15 to 20 days. Adding a database (Railway offers free PostgreSQL and Redis with limitations) consumes credit faster.
Best for: Traditional server applications, APIs that need persistent connections or WebSockets, projects that need a real database, and applications where cold starts are unacceptable.
Fly.io: Global Distribution for Free
Fly.io takes a different approach — they run your application in lightweight VMs (using Firecracker) distributed across data centers worldwide. The free tier is generous enough to run a small but real production service.
The good: Your API runs in actual VMs with dedicated resources, not shared serverless functions. You get global distribution by default — deploy to one region, then scale to others with a single command. Persistent volumes are available for applications that need local storage (like SQLite databases). The performance characteristics are predictable because you are not sharing a runtime with other tenants.
The bad: The initial setup has a steeper learning curve than Vercel or Railway. You need to understand their fly.toml configuration file, and deploying non-standard stacks sometimes requires writing a Dockerfile. The free tier requires a credit card on file, even though you will not be charged.
Cost breakdown for the free tier:
- Up to 3 shared-cpu-1x VMs with 256MB RAM each
- 3GB persistent volume storage total
- 160GB outbound data transfer per month
- Unlimited inbound data
When it breaks free: If you need more than 3 VMs, more than 256MB RAM per VM, or more than 3GB of storage, you start paying. The compute pricing is reasonable (around $2/month for a shared CPU VM), but it adds up if you need multiple services.
Best for: APIs that need to be globally distributed, applications using SQLite or other local storage, services that benefit from always-on VMs, and projects where you want predictable performance.
Cloudflare Workers: The Edge Computing Option
Cloudflare Workers run your code on Cloudflare's global edge network — over 300 data centers worldwide. The execution model is fundamentally different from traditional servers: your code runs in a V8 isolate (the same engine that powers Chrome), and each request gets its own lightweight execution context.
The good: The performance is exceptional. Because your code runs on edge servers close to users, latency is consistently low — often under 10ms for cached responses. The free tier is generous with 100,000 requests per day (not per month). Cold starts are measured in milliseconds, not seconds, because V8 isolates spin up much faster than containers.
The bad: The runtime environment has significant limitations. You cannot use Node.js APIs directly — no fs, no child_process, no native modules. The Worker must respond within 10ms of CPU time on the free plan (wall clock time can be longer for I/O). This means CPU-intensive operations like image processing are not feasible. The maximum script size is 1MB on the free tier.
Cost breakdown for the free tier:
- 100,000 requests per day
- 10ms CPU time per invocation
- 1MB script size limit
- Workers KV: 100,000 reads/day, 1,000 writes/day
- R2 storage: 10GB stored, 10 million reads/month, 1 million writes/month
When it breaks free: The per-day limits are generous for most projects. If you exceed 100,000 daily requests, the paid plan ($5/month) gives you 10 million requests per month with 50ms CPU time. The bigger issue is usually the runtime limitations rather than the quotas.
Best for: Lightweight API proxies, authentication middleware, URL shorteners, JSON APIs that do not need heavy computation, and any API where global low latency is the primary requirement.
Comparing Real-World Costs
Let us put some numbers on this. Suppose you have a JSON API that serves 50,000 requests per day with an average response size of 5KB.
Monthly traffic: ~1.5 million requests, ~7.5GB bandwidth.
- Vercel: Free. Well within the 100K invocations/month limit if you cache aggressively. But you will need to handle cold starts.
- Railway: Borderline free. The compute cost of running 24/7 may exceed the $5 credit, especially with database usage.
- Fly.io: Free. A single shared-cpu VM with 256MB RAM handles this easily, with bandwidth well under the 160GB limit.
- Cloudflare Workers: Free. 50K requests/day is half the daily limit. But you need to ensure your API logic fits within the runtime constraints.
For our use case at MC Heads — an image API with significant compute requirements for rendering — we found that a combination of Fly.io for the origin server and Cloudflare for CDN caching gave us the best results. The origin server handles the relatively small number of cache misses, while Cloudflare absorbs the vast majority of traffic at the edge.
Hybrid Approaches
In practice, the best free hosting setup often combines multiple platforms. Here are some patterns that work well:
Cloudflare Workers + Fly.io: Use Workers as a caching and routing layer in front of a Fly.io origin server. The Workers handle the vast majority of requests from cache, and only cache misses hit the origin. This gives you global edge performance with the full flexibility of a real server for complex operations.
Vercel + Railway: Host your frontend and lightweight API routes on Vercel, with a Railway backend for compute-intensive operations or persistent workloads. Vercel handles the web traffic, Railway handles the heavy lifting.
Cloudflare Workers + R2 + KV: For APIs that primarily serve static or semi-static data, you can build the entire stack on Cloudflare. KV for fast key-value lookups, R2 for larger objects, and Workers for the routing logic. This is the cheapest option at scale because Cloudflare's egress pricing is $0.
Practical Tips for Staying Free
After years of running services on free tiers, here are the tactics that actually matter:
Cache aggressively. The single biggest factor in staying under free tier limits is not serving the same data twice. Set proper Cache-Control headers, use a CDN, and cache at every layer.
Sleep when idle. If your platform supports it, configure your application to sleep after a period of inactivity. Railway and Fly.io both support this. You lose the always-on guarantee but gain significant credit savings.
Monitor your usage. Every platform provides usage dashboards. Set up alerts before you hit 80% of your limits so you are not surprised by a bill.
Optimize your responses. Smaller responses mean less bandwidth. Use gzip compression, minimize JSON payloads, and avoid sending unnecessary data.
Choose the right platform for your workload. A CPU-intensive API on Cloudflare Workers will hit CPU limits quickly. A rarely-accessed API on Railway will waste compute credits staying idle. Match your workload characteristics to the platform's strengths.
The Bottom Line
Free API hosting in 2026 is genuinely viable for small to medium projects. The platforms have matured, the free tiers are generous, and the trade-offs are well-understood. Start with the platform that best matches your technical requirements, add caching to stretch your limits, and upgrade to a paid plan only when your traffic justifies it.
The best part: most of these platforms make it trivial to upgrade. You are not locked in to a free tier architecture that cannot scale. Build it free, prove the concept, and pay for infrastructure only when your project has earned it.