Customer Docs
Public Asset URLs and On-the-Fly Transforms
Customer-facing documentation for onboarding, deployment, storage providers, AI providers, and migration planning.
Public Asset URLs and On-the-Fly Transforms
Status: PUBLISHED Last updated: 2026-04-26 Applies to: All plans
What it does
Every asset has a stable, ImageMan-domain URL of the form https://<your-imageman-host>/i/<asset-id>. You can append query parameters to resize or convert the image without re-uploading.
When to use it
- You want to embed an asset in a marketing site, email, or app and not expose your bucket.
- You need different sizes (thumbnail, hero, retina) of the same image.
- You want to convert from JPEG to WebP/AVIF for smaller payloads.
Step-by-step
- Open any asset in the dashboard.
- In the asset drawer, click Asset URL (or the copy icon in the action bar). The clipboard now has your stable URL.
- Paste it into your
<img src="...">or your CMS. - To resize, append
?w=400. To set a height too:?w=400&h=300. To change format:?format=webp.
Supported transforms
| Param | Type | Default | Notes |
|---|---|---|---|
w | integer (1–4096) | — | Target width in px. |
h | integer (1–4096) | — | Target height in px. |
format | jpeg | png | webp | avif | original | Output format. |
q | integer (1–100) | 85 | Encoder quality. |
fit | cover | contain | fill | inside | outside | inside | Resize strategy. |
How it works
- No transform? The URL 302-redirects to a freshly signed storage URL. Your bytes are served directly by the CDN — fast and cheap.
- With a transform? img-man resizes on demand, caches the result for an hour at the edge, and streams it back.
- The signed storage URL behind the redirect rotates frequently. Your
/i/<id>URL stays stable.
Tips & limits
- The asset ID in the URL is the bearer credential — anyone with the link can fetch the asset. For private content, use a share link instead.
- Maximum dimension per axis is 4096 px.
- Only image formats can be transformed; non-image assets (PDFs, etc.) redirect to the original.
Troubleshooting
| Problem | Cause | Fix |
|---|---|---|
404 from /i/<id> | Asset was deleted or wrong ID. | Re-copy the URL from the drawer. |
| Wrong domain in copied URL | NEXT_PUBLIC_APP_URL not set on the server. | Set NEXT_PUBLIC_APP_URL in your environment. |
| Transformed image is bigger than expected | withoutEnlargement is on; we never upscale. | Provide a smaller source or accept the upper bound. |
Related
- Sharing — for private/expiring links.
- Transform rules — saved presets and signed-transform support are still on the roadmap.
Source: customer-docs/features/public-asset-url.md