One Upload, Every Size a Listing Needs
Storing a photo returns a handle. Each size the listing page asks for is a path segment on that handle’s URL, rendered on first request and cached at the edge after that.
Three Steps Behind Every Listing Page
Photos and documents take the same path, from the agent’s phone to the buyer’s browser.
Global CDN Delivery
Photos go from the browser to storage in one request. The response carries the handle every later call uses.
Transform
Resize, crop, compress, watermark and convert format by editing the URL. Every variant comes from the one stored file.
Deliver
Each variant renders once at the edge and serves from cache after that, on a CDN tuned for image heavy pages.
The Same Pipeline in a Working App
Horizon Pro is a listings marketplace on the Filestack File API. Every image on it is a transformation of the handle its upload returned.
Photos land as handles
Three photos go straight from the browser to storage. Each response carries a handle, and the first becomes the cover.
Explore Uploads
Documents take the same path
Disclosures, floor plans and HOA documents upload like photos do, in PDF, DOC, XLS and image formats.
Explore Document Processing
The panel writes the URL
Size, filter and format controls rewrite the CDN URL, and the listing page requests exactly that URL.
View Processing Docs
Search runs on the same files
Cards request an 800px WebP variant. Filters live in the query string, so a filtered view is a shareable link.
Open the live demo
Galleries That Load From the Edge
A listing page is mostly photographs. The hero and the thumbnail strip are separate transformations of the same three handles.
- WebP output set per variant in the URL
- Thumbnails at 200×150, heroes at 1200×800
- Signed URLs and access policies for private listings
- Cached at the edge after the first request
Six Services, or One URL
Putting one listing photo on a page takes six services. Filestack runs all six and hands you the URL.
Or write one URL
Filestack runs all six of those jobs behind that URL, including the multipart uploads and the retries. Changing a size means editing the path.
Frequently Asked Questions
Can Filestack handle high volume listing photo uploads?
Yes. Uploads are chunked, multipart and resumable, so an agent can send dozens of photos at once from a phone on a cellular connection. Retry configuration and cancel tokens are part of the SDK.
How are listing images delivered?
Through the Filestack CDN. Each transformed URL is computed on first request and cached at the edge from then on. Output format is set per variant in the URL, or left to auto_image.
Can I generate different sizes of the same photo?
Yes. One stored file backs every size. Thumbnails, gallery sizes and full screen variants are separate transformation URLs on the same handle, each rendered on demand.
How do private and pre-market listings stay protected?
Signed URLs and access policies scope a file to a user, a session or an expiry, so off-market and pocket listings stay available to the people who should see them.
Does Filestack handle documents as well as photos?
Yes. Disclosures, inspection reports and floor plans upload through the same endpoint as photos, and document conversion covers 17 formats.
Can I see the code behind the demo?
Yes. Horizon Pro is a Next.js app, and the build guide covers the upload function, the drop zone, the transformation presets and the search filters.