Image Caching
How Image Caching Works
RenderStack caches rendered images to improve performance and reduce unnecessary API usage. When you request the same render with identical parameters, RenderStack serves the cached version instead of
How Caching Works#
When you render an image via the API, RenderStack generates a cache key based on:
- The template being rendered
- The dynamic layer data you provide
- The output format and quality settings
If a render with the same parameters has been generated before and is still in the cache, the cached image is returned immediately without re-rendering. This is significantly faster and does not count against your render quota.
Cache Limits by Plan#
Each plan has a maximum number of cached images:
| Plan | Max Cached Images |
|---|---|
| Starter | 50 |
| Pro | 500 |
| Business | 2,000 |
| Enterprise | 10,000 |
When the cache is full, the oldest entries are removed to make room for new ones.
Cache Invalidation#
Cached images are automatically invalidated when:
- The underlying template is modified (changing any layer, canvas size, or settings)
- The cache entry expires or is evicted due to capacity limits
Bypassing the Cache#
If you need a fresh render regardless of cache status, you can force a new render by including a unique parameter in your API request (e.g., a timestamp or random value in a hidden layer).
Dynamic Image URLs#
Cached images are especially beneficial for Dynamic Image URLs (GET-based rendering), where the same URL may be requested many times by different viewers. The cache ensures fast response times for repeated requests.