ImageKit Architecture

Design principles that ensure billions of assets are delivered fast, reliably, and securely.

ImageKit powers thousands of websites and apps, processing and delivering billions of images and videos every day. Our platform is trusted by some of the largest e-commerce, media, and digital businesses worldwide.

To sustain that scale while keeping latency low and availability high, we’ve built a deeply optimized, globally distributed, multi-layered architecture.

Below is a high-level overview, followed by deeper dives into each tier.

  1. Global CDN Layer: We leverage Amazon CloudFront as our primary CDN, ensuring that content is cached close to end-users across a global network of edge locations for lightning-fast delivery. If needed, you can also integrate your own CDN.
  2. Distributed Origin Servers: We operate multiple origin clusters across six AWS regions worldwide, ensuring low-latency processing and redundancy. If one region becomes unavailable, traffic is automatically routed to the next closest operational region—ensuring exceptional uptime and resilience.

Let’s dive deeper into how ImageKit works behind the scenes.

How it works

A request–response cycle lands in one of three paths:

  1. Cached at Edge (CDN Hit): If the requested image or video is already cached at the CDN edge, the user is served instantly from the nearest edge location.
  2. Cached at Origin: If not available at the edge, but cached at the nearest ImageKit origin server, the asset is served from there with minimal latency.
  3. Fresh Request (Origin Fetch + Process): If the asset is neither cached at the edge nor the origin, the nearest origin server fetches it from your configured storage (AWS S3, GCS, Azure Blob Storage, or ImageKit's Media Library), processes it on-the-fly, caches it, and returns it to the user.

With a default one-year TTL, most customers achieve a 95%+ edge cache hit ratio, resulting in lightning-fast latency—often as low as 20ms, for the majority of requests. Even when a cache miss occurs, it is processed and served quickly—in just a few milliseconds, as we'll explore later in this section. This is crucial because every page load can have some cache misses, and minimizing their impact is key to delivering a consistently fast experience.

To see this in action, open this image in a new browser tab, reload it, and check the network timings.

When served from the CDN edge, you’ll typically see load times in the tens of milliseconds range. For reference, when tested from Delhi, the image loaded in around 20ms — your results may vary slightly based on your location and network conditions.

What happens on a cache miss?

Here’s the complete flow when the asset is not cached at the edge:

  1. The request is routed to the nearest ImageKit origin server (across six global regions). If the nearest server is not the account’s designated home region, we internally forward the request to the home region for processing.
  2. Origin server checks internal caches. If found, the asset is immediately served.
  3. Otherwise, the origin fetches the asset from your storage or ImageKit's Media Library.
  4. The asset is processed in real-time, cached, and then sent back to the edge node.
  5. Finally, the processed asset is delivered to the user.

Here’s a visual diagram summarizing this flow:

For images, this entire pipeline completes in milliseconds, ensuring a seamless user experience. For videos, processing takes slightly longer due to chunking and encoding, but remains highly optimized.

Below is a real snapshot from our Grafana dashboard showing encoding times for all requests processed via our Mumbai region:

  • p50: ~70ms
  • p90: ~180ms

These numbers — including a p99 of roughly 450 ms even with complex transformations like AVIF generation and text overlays — highlight the efficiency of our real‑time media pipeline.

Multi-region processing

Latency grows with distance, and the speed of light in fiber is our hard ceiling—about 2,00,000 km/s, or roughly 10ms of round-trip time for every 1000 km of cable. This means if an asset stored in us-east-1 has to be processed in ap-south-1 (Mumbai)—a path of ~13000 km alone adds ~130ms before we account for routing and queuing delays.

To avoid that penalty, ImageKit runs origin clusters in six AWS regions, always processing in the region closest to your storage bucket:

  • Shorter distance, lower latency. Moving the work nearer to your data shaves tens to hundreds of milliseconds off every miss.
  • Lower inter-region egress costs. No surprise data-transfer charges for crossing AWS regions.
  • Built-in resilience. If a region is impaired, traffic fails over to the next-closest cluster with zero manual intervention.

End-to-end path

  1. User → CloudFront edge. Last-mile latency is capped at ~20–100 ms thanks to 700+ PoPs worldwide.
  2. CloudFront edge → ImageKit origin. Traffic stays on the AWS global backbone, bypassing the public internet for a stable, high-throughput hop.
  3. Origin → Storage (same region). Minimal round-trip time and no inter-region egress cost.
  4. Process, cache, return.

This design keeps the cold-miss path fast everywhere: even the first request for a brand-new variant is usually back to the user in a few dozen milliseconds, with subsequent hits served instantly from the nearest edge cache.

Virtually unlimited storage

When you use the ImageKit Media Library, you get access to virtually unlimited storage capacity — powered by AWS S3’s massively scalable and highly durable backend.

Uploads to ImageKit (upload.imagekit.io) are optimized for speed and reliability through AWS Latency-based Routing across six global regions. This means upload requests are automatically routed to the nearest available region, minimizing round-trip times and ensuring a smooth experience — even for large assets like high-resolution videos or batch uploads. The assets are ultimately stored in the selected processing region, ensuring data compliance.

No matter where your users or teams are located, you can expect fast, resilient uploads with minimal latency.

Scaling

ImageKit’s workloads are orchestrated on Kubernetes, enabling us to elastically scale infrastructure up or down based on real-time traffic demands. Our architecture is designed to automatically absorb unpredictable traffic spikes without human intervention, maintaining both low latencies and consistent quality of service even during peak loads.

We proactively run large-scale load tests, simulating real-world traffic patterns across different regions and scenarios, to continuously validate and tune our scaling strategies.

In addition, we conduct regular chaos engineering exercises — intentionally introducing failures and resource constraints — to ensure that our system can gracefully recover from unexpected disruptions without affecting customer experience.

This focus on resilience and proactive testing allows us to confidently support everything from steady-state workloads to viral traffic surges, while delivering fast, reliable media experiences at scale.

Uptime

We officially commit to a 99.9% uptime SLA, but in practice, we strive for 100% availability and consistently deliver well above 99.9% uptime, as publicly tracked on our status page.

To be candid, 99.9% uptime allows for around 43 minutes of downtime per month — a level of disruption that most modern applications cannot really afford. Thankfully, our real-world performance is much closer to 99.99% uptime, with downtime measured in mere minutes, if any.

Technically, our uptime is bounded by AWS CloudFront’s SLA, which also commits to 99.9% availability, but with our architecture and monitoring, we consistently aim — and deliver — far higher.

Security

Security is deeply ingrained in ImageKit’s architecture and operational practices.

  • We are ISO 27001 certified, following globally recognized standards for information security management.
  • We undergo regular third-party security audits and penetration tests to validate and strengthen our defenses.
  • We implement multiple layers of security across our stack — including encryption at rest and in transit, robust authentication mechanisms, strict access controls, and continuous monitoring.

Protecting customer data is foundational to how we design, build, and operate the platform — not an afterthought.

You can learn more about our security posture here:
Security & Trust | GDPR Compliance