15. Serving Images from Static Folders in Jinja2

FastAPI Static File Handling

FastAPI serves static files such as images through explicit static directory mounting. This approach ensures that binary assets are delivered efficiently without passing through application logic. Proper static file configuration is essential for predictable asset resolution in server-rendered applications.

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles

app = FastAPI()
app.mount("/static", StaticFiles(directory="static"), name="static")

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Referencing Images Inside Jinja Templates

Images stored in the static directory are referenced in Jinja templates using their mounted URL paths. This keeps templates declarative and avoids hard-coding filesystem locations. Correct referencing ensures portability across environments and deployment setups.

<img src="/static/images/logo.png" alt="Logo">

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Common Pitfalls with Paths and Asset Loading

Incorrect directory structures or mismatched URL paths often cause assets to fail loading. Relative paths, missing mounts, or incorrect environment configurations are frequent sources of error. Understanding how FastAPI maps URLs to filesystem paths helps avoid these issues and simplifies debugging.