ImageKit signed URLs: encode before signing

Not specified by the original author.

TL;DR

For ImageKit signed URLs, encode the URL first and then sign it, per the docs, not the other way round. And if a transformation does not exist in your SDK, build the URL string by hand from the documented transformation codes, the SDK may simply not expose it.

Steps

1. For ImageKit signed URLs, encode the URL first and then sign it, per the docs, not the other way round.
2. And if a transformation does not exist in your SDK, build the URL string by hand from the documented transformation codes, the SDK may simply not expose it.

When to use

You are seeing this: For ImageKit signed URLs, encode the URL first and then sign it, per the docs, not the other way round. Use this skill when you run into "ImageKit signed URLs: encode before signing".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: API research notes (thecyrilcril/laravel-imagekit, 2026-08-28 ImageKit API vs SDK study): documents two real gotchas from comparing docs against SDK behavior. First, the docs say signed URLs are built by encoding the URL then signing, but the SDK signs a decoded version, so URLs with special characters fail signature validation when built the SDK way. Second, the SDK only maps about 30 transformation aliases against roughly 65 documented transformation codes, with no layers, AI, video, or conditional support, so complex transformations need hand-built URL strings.

Verified resolution: For ImageKit signed URLs, encode the URL first and then sign it, per the docs, not the other way round. And if a transformation does not exist in your SDK, build the URL string by hand from the documented transformation codes, the SDK may simply not expose it.

Source URL: https://github.com/thecyrilcril/laravel-imagekit/blob/HEAD/docs/research/2026-08-28-imagekit-api-vs-sdk.md