Vercel vs Fastly

Vercel and Fastly both make web applications fast and secure, but they cover different parts of the stack. Vercel is a full-stack cloud platform where hosting, CDN, security, and compute are all built in. Push code and the platform builds, runs, and serves your application globally. Fastly is an edge infrastructure layer that sits in front of your existing origin servers, providing caching, compute, and security that you configure and manage separately from your hosting.

A common question that teams ask is whether Fastly belongs in front of Vercel. For the majority of web applications, it doesn't. Vercel already includes a global CDN with 126+ Points of Presence (PoPs), edge caching with framework-aware invalidation, DDoS protection, WAF, and bot management on every plan. Adding Fastly in front of Vercel adds complexity without improving what Vercel already handles automatically. Fastly makes sense when you manage your own hosting and need infrastructure-grade CDN control through Varnish Configuration Language (VCL), shielding, segmented caching, video streaming, real-time messaging, or edge programmability through WebAssembly.

This guide compares Vercel and Fastly across architecture, CDN, security, compute, AI, developer workflow, and pricing to help you decide which platform fits your project.

• How Vercel and Fastly compare
• Vercel platform deep dive
• Fastly-specific capabilities
• Which features are self-serve vs sales-assisted
• When to choose Vercel or Fastly
• Get started with Vercel

Vercel includes hosting, CDN, security, and compute as one platform. You deploy to Vercel and everything works together automatically. Fastly is a layer you add in front of your own hosting (AWS, GCP, your own servers) to handle caching, edge compute, and security. With Fastly, you're responsible for the origin infrastructure behind it.

Vercel handles hosting, builds, and deployment in one place. Fastly expects you to bring your own origin and CI/CD pipeline.

Vercel derives caching behavior from your framework configuration, so ISR (Incremental Static Regeneration), stale-while-revalidate, and tag-based invalidation work without manual setup. Fastly requires you to define every caching decision yourself through VCL or Compute code and three distinct cache interfaces.

Vercel's invalidation is framework-integrated. A single revalidateTag() or revalidatePath() call propagates globally in ~300ms with no manual API calls or VCL logic required. Fastly's purge is faster at ~150ms, but requires API calls or VCL-based purge logic that teams configure themselves.

Fastly's caching architecture reflects its infrastructure focus. Shielding (62+ designated cache locations across 6 continents) routes cache misses through a chosen POP before hitting the origin, reducing origin load. Clustering pairs two POPs to share cache, and together they provide up to 4 layers of request collapsing. Soft purge marks content stale rather than deleting it, enabling graceful revalidation. Segmented caching handles unlimited-size objects for VCL services, and Edge Side Includes (ESI) enables fragment-based caching within a page.

Both platforms provide web application security, but they package it differently. Vercel includes DDoS, WAF, and bot protection active on all plans with no configuration required. Fastly offers security product depth across 8 product areas, with specialized products for infrastructure-level concerns like client-side script control and API inventory.

Fastly also provides Client-Side Protection, which inventories and controls client-side scripts to help meet PCI DSS 4.0.1 requirements (Sections 6.4.3 and 11.6.1), and API Security for passive discovery of APIs flowing through the edge network with shadow API identification.

Vercel focuses application-layer security on WAF, DDoS, and bot protection. TLS fingerprinting (JA3 and JA4 on all plans) identifies clients by their TLS handshake patterns, which helps detect automated traffic that spoofs browser headers.

Both platforms run code at the edge, but the compute models serve different workload patterns. Vercel Fluid Compute handles full application workloads with server-like resource limits and active CPU pricing. Fastly Compute is optimized for short, fast edge transformations compiled to WebAssembly.

Fluid Compute keeps pre-warmed instances running on paid plans. Across the platform, 99.37% of all requests see zero cold starts. Bytecode caching reduces startup time for the remainder. Multiple invocations share a single instance with error isolation, meaning one broken request won't crash others. Active CPU pricing bills only during code execution, not during I/O wait. Time spent waiting for database queries, API responses, or AI model inference does not count toward compute costs.

Fastly Compute compiles all code to WebAssembly, supporting Rust (40+ tested crates), JavaScript/TypeScript (~30 compatible modules), and Go. The tighter resource envelope (50ms CPU, 128 MB heap) reflects the optimization for request-level edge logic rather than long-running application workloads. Compute can also generate responses without a traditional origin using synthetic responses, edge-side templating, or the includeBytes() JS SDK function that embeds static files into the WASM binary at compile time. These patterns work well for lightweight edge-native apps, but most production workloads still require a separate origin behind Fastly. Service chaining routes requests between up to 3 services in the same POP with no network hop. VCL provides a separate programming model for CDN-level logic, including request routing, cache manipulation, and backend selection.

The comparison tables above show where Vercel and Fastly overlap. The sections below go deeper into how each capability works on Vercel.

Vercel reads framework patterns and provisions the best possible infrastructure automatically. Your code defines what it needs to run, and each commit becomes an immutable, production-ready environment. Everything is configurable when you need it, but the defaults mean most teams never have to touch infrastructure settings.

Caching is also framework-derived. ISR rebuilds pages on demand with ~300ms global invalidation using up to 128 cache tags per response. Layered cache control headers (Vercel-CDN-Cache-Control, CDN-Cache-Control, Cache-Control) let you set different TTLs for the Vercel CDN, downstream CDNs, and browsers. Stale-while-revalidate and stale-if-error provide cache resilience, and request collapsing groups concurrent requests into one backend call. Built-in image optimization converts to WebP and AVIF formats with edge caching.

The global CDN spans 126+ PoPs across 51 countries with 20 compute-capable regions.

Fluid Compute is a hybrid serverless model providing serverless flexibility with server-like performance. Pre-warmed instances on paid plans eliminate cold starts for 99%+ of requests, while bytecode caching reduces startup time for the remainder. Multiple invocations share a single instance with error isolation, auto-scaling to 30,000 concurrent on Pro or 100,000+ on Enterprise.

Active CPU pricing bills only during code execution, not I/O wait time. The waitUntil API allows background work to continue after the response is sent.

Build machine tiers range from Standard (4 vCPU, 8 GB) through Enhanced (8 vCPU, 16 GB) to Turbo (30 vCPU, 60 GB). Framework detection provisions compute automatically, so Next.js gets server components, ISR, image optimization, and streaming while SvelteKit and Astro deploy with SSR out of the box.

Every request passes through platform-wide protections before reaching your application, with no configuration required.

DDoS mitigation operates at L3, L4, and L7 using hundreds of detection signals, and only legitimate traffic is metered. The Vercel Firewall executes in a defined order: DDoS mitigation, then IP blocking, then custom rules, then managed rulesets. WAF changes propagate globally within 300ms with instant rollback.

WAF custom rules are available on all plans. Bot Protection Managed Ruleset challenges non-browser traffic, and the AI Bots Managed Ruleset lets you log or deny AI crawlers. BotID is an invisible CAPTCHA that uses AI to distinguish bots from real users without visible challenges. Basic validation is free on all plans, and Deep Analysis ($1/1K calls on Pro/Enterprise) adds advanced signal analysis for sophisticated bots.

Rate limiting is available on all plans with fixed window (basic) and token bucket for smoothed bursting on Enterprise. The @vercel/firewall SDK provides programmatic control.

Secure Compute provides dedicated VPC, static egress IPs, and VPC peering for workloads that need network isolation.

Vercel maintains compliance certifications including SOC 2 Type 2, ISO 27001:2022, PCI DSS v4.0, GDPR, TISAX AL2, and EU-U.S. Data Privacy Framework. HIPAA BAA is available on Enterprise.

Building AI applications requires accessing multiple models, handling provider outages, and managing costs. Vercel provides infrastructure across all three areas.

AI Gateway routes requests to 20+ providers (OpenAI, Anthropic, Google, xAI, Groq, and more) through a single endpoint with configurable fallback chains when a provider is slow or down. Bring your own API keys with no added fees. Automatic prompt caching (exact-match) reduces redundant API calls.

AI SDK provides core primitives for text generation, streaming, structured data extraction, and tool calling. Agent orchestration works with waitUntil for background processing after the response is sent.

Vercel Sandbox lets AI agents and user-generated code run safely in isolated microVMs with millisecond startup. Teams use it for code playgrounds, AI-powered builders, and executing agent output in a controlled environment.

Vercel Agent provides AI-powered developer tools. Code Review scans PRs for bugs, security issues, and performance problems and generates validated patches you can merge. Investigation traces error alerts to root cause across logs, code, and deployments.

Every branch push generates a unique preview deployment URL with protection options including password, Vercel Authentication, and Trusted IPs.

Rolling Releases provide gradual traffic shifting with dashboard metrics comparing canary vs current. Instant Rollback reassigns domains without rebuilding.

Collaboration tools extend beyond code:

• Free unlimited Viewer seats on Pro/Enterprise, so designers, PMs, and reviewers don't consume paid licenses
• Vercel Toolbar with Layout Shift Tool, Interaction Timing, Accessibility Audit, and in-browser Feature Flag management
• Comments on preview deployments with issue tracker integration (Linear, Jira, GitHub)
• Edit Mode with 8 CMS integrations for visual content editing
• Draft Mode for previewing unpublished CMS content
• Managed DNS (ns1.vercel-dns.com, ns2.vercel-dns.com)
• OIDC Federation for credential-free connections to AWS, GCP, and Azure

Fastly's developer workflow is built for infrastructure operators. You deploy through the CLI (fastly compute publish) and activate specific service versions manually. There are no automatic preview URLs per branch. Staging environments require manual DNS or hosts file changes. Fastly provides a browser-based playground (Fiddle) for testing VCL and Compute code, a local dev server (Viceroy), and a Terraform provider for managing services as infrastructure-as-code.

Vercel focuses on what the user experiences. Speed Insights tracks Core Web Vitals (FCP, LCP, INP, CLS) with element attribution on all plans. Web Analytics is privacy-first with no cookies and a daily-reset hash, with custom events on Pro. Session Tracing via the Vercel Toolbar visualizes request flows in the dashboard.

Log Drains export to external endpoints at $0.50/GB on Pro/Enterprise. OpenTelemetry support includes Datadog, New Relic, and Dash0 integrations. Real-time usage dashboards show function invocations, error rates, and duration metrics. Observability Plus extends log retention to 30 days ($10/mo + $1.20/1M events on Pro).

Fastly focuses on infrastructure-level visibility. You can see how each edge location is performing, how much load your origin servers are handling, and where latency is coming from at the network level. Fastly includes real-time log streaming to 37+ destinations (Datadog, Splunk, S3, BigQuery, and more) at no extra cost. Some advanced tools like Domain Inspector and Origin Inspector are paid add-ons.

Teams often pair application-level observability (Web Vitals, real-user monitoring) with infrastructure-level monitoring (per-POP performance, origin latency), which is why both platforms support export to external APM tools.

Vercel pricing includes hosting, CDN, security, image optimization, analytics, and framework infrastructure in a single bill with transparent per-resource costs.

Active CPU pricing excludes time spent waiting on databases, APIs, or AI model responses. Spend Management sends notifications at 50%, 75%, and 100% thresholds. Regional pricing is published for all 20 regions so you can choose regions based on cost and latency tradeoffs.

Fastly offers specialized capabilities that fall outside Vercel's focus areas. If your project relies on any of these, Fastly may be worth evaluating alongside Vercel.

Fastly provides dedicated video infrastructure, including live streaming, video-on-demand, adaptive bitrate playback, and On-The-Fly Packaging (OTFP), which transmuxes between container formats at the edge in real-time. Fastly's Streaming Miss feature streams responses to clients while writing to cache at the same time, reducing time-to-first-byte on cache misses. Vercel is optimized for web application delivery, and teams with video workloads typically pair their application platform with a dedicated video CDN.

Fastly's Fanout provides managed pub/sub for persistent connections, supporting WebSockets, Server-Sent Events (SSE), and Long-Polling over a single API. WebSockets passthrough offers direct pipes from client to origin. A separate Pub/Sub App adds MQTT support for IoT workloads. Vercel functions support streaming responses and the waitUntil API for background processing. For persistent bidirectional connections, teams on Vercel typically add a dedicated real-time service through the Vercel Marketplace.

Fastly's AI Accelerator caches LLM API responses and serves cached results for semantically similar queries using a configurable similarity threshold (default 0.75, max 30-day TTL). It supports OpenAI, Azure OpenAI, Gemini, and any OpenAI-compatible API. When multiple users ask similar questions, AI Accelerator can reduce latency and LLM API costs by serving from cache. Vercel AI Gateway provides multi-provider routing with automatic exact-match prompt caching, while Fastly's similarity-based approach addresses a different optimization. Fastly does not provide multi-provider routing, an AI application SDK, or sandboxed code execution.

Fastly provides three cache interfaces that give infrastructure teams precise control over caching behavior. Shielding (62+ locations across 6 continents) and clustering provide up to 4 layers of request collapsing. Segmented caching handles unlimited-size objects for VCL services. Edge Side Includes (ESI) enables fragment-based caching within a page. VCL controls every cache decision at the code level. Vercel takes a different approach: caching is framework-integrated through ISR, tag-based invalidation, and layered cache headers, so the right caching behavior is applied automatically based on how your application is built.

This table shows what each platform includes out of the box versus what requires additional purchases or sales conversations to access.

The right platform depends on what you're building and what role the platform plays in your stack.

Teams building web applications, AI workloads, or projects where hosting, CDN, security, and observability should work together without manual assembly will find Vercel's architecture suited to their needs. Teams needing deep CDN control, video delivery, real-time messaging, or edge programmability at the infrastructure level will find Fastly's configurable approach fits their requirements.

Both Vercel and Fastly deliver web content globally with different tradeoffs. Vercel provides an integrated application platform. Fastly provides configurable edge infrastructure.

With Vercel, you push your code and the platform handles the rest. Framework detection, global CDN, security, and scaling happen automatically on every deploy.

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