Can I combine CC BY-SA material with other licences?

Decide before you start whether your use is an adaptation or a mere collection. That single decision determines everything. The ShareAlike condition triggers only when you share Adapted Material. Gather separate works into a single container and it does not. If you do adapt, the result must carry the same license, BY-SA 4.0 or one Creative Commons has formally designated as compatible. No other license will do. Then check the NoDerivatives status of every input and the adapter-license requirement of every ShareAlike input. Only then begin.

What A Collection Is

Treating every combination as an adaptation is the single most frequent mistake. Under the 4.0 legal code, a collection keeps each work intact. Think of a binder of separate essays or a playlist of songs. Each work keeps its own license. The collection license, if you apply one, covers only your editorial arrangement and new material you add, an introduction, cover art. It does not convert the individual works to a new license.

What An Adaptation Is

An adaptation reworks the work in a way that requires copyright permission. Translation is normally an adaptation. Synchronising music with a moving image is expressly Adapted Material under 4.0. Cropping, excerpting, editing or combining may or may not create an adaptation under your jurisdiction's copyright law. Do not assume these actions are safe without checking.

Building a website that displays separate CC BY-SA images alongside CC BY text, each with its own attribution and license notice? You are making a collection. Cutting the image into your video timeline and adding voiceover? You are making an adaptation. The first is straightforward. The second triggers ShareAlike and requires you to license your new video under BY-SA 4.0 or a compatible license.

Check For ND First

Check every input for an ND condition. If any component uses CC BY-ND 4.0, CC BY-NC-ND 4.0, or an older version with NoDerivatives, you cannot share an adaptation that includes that component. The ND license permits sharing the unaltered work and making private adaptations. It does not permit distributing the modified version. A single ND input blocks the entire combined adaptation from being shared. Your only options: remove that input, get separate permission from the licensor, or keep the adaptation private.

Then Test ShareAlike

If no input carries ND, test ShareAlike. Every SA-licensed input demands the adaptation you share use the same SA license, BY-SA or BY-NC-SA depending on the original, or a license Creative Commons has formally named as compatible. The official compatibility list is the only authority. Do not assume two SA licenses work together. Creative Commons lists one-way compatibility from BY-SA 4.0 to GPLv3 for adapted material. This does not turn a CC license into a software license or create reverse compatibility.

Combine a CC BY-SA photograph with a CC BY-SA song to make a new video, and your video must carry CC BY-SA 4.0 or a compatible license. Combine CC BY-SA material with CC BY-NC-SA material, and the adaptation must satisfy both SA conditions. The more restrictive of the two, noncommercial, will govern the whole adaptation. The NC condition is not overridden by SA. The result is an adaptation that must be shared only under CC BY-NC-SA 4.0 or a compatible noncommercial SA license.

When you share an adaptation of CC BY-SA material, your own contribution is covered by the license you apply to the adaptation. The original work's license notice must remain intact and visible. You cannot sublicense the original material. Downstream recipients receive the same license offer from the original licensor. Your adaptation license applies only to the new elements you added, the editing, voiceover, arrangement. Not to the pre-existing work.

Create a video using a CC BY-SA clip and your own commentary, license the video under CC BY-SA 4.0, and someone else can reuse the entire video under the same SA conditions. They must attribute both the original clip creator and you, follow the ShareAlike rule for any further adaptation, and retain all notices. If you later want a different license for your contribution, you cannot. The adaptation you shared has already attached the SA condition to the whole work. The only way to avoid this is to get separate permission from the original licensor to release the combined work under a different license. Or never share the adaptation at all.

Three Failure Points

Combining CC BY-SA material with other licenses fails in three common scenarios. First, an input uses NoDerivatives and you plan to adapt it. The combination is unshareable. Second, two inputs carry incompatible SA licenses, such as BY-SA 4.0 and BY-NC-SA 4.0, and you cannot satisfy both conditions. Third, the adaptation's required license conflicts with the platform's terms of service. A platform that demands an exclusive sublicense creates a conflict the CC license does not permit.

Fix Each One

In the first scenario, remove the ND input or seek separate permission. In the second, use only inputs that share the same SA condition, or rely on the official compatibility list. The Creative Commons compatibility page names the exact licenses that satisfy an SA requirement. Do not guess. If the list does not name a license, that license is not compatible, however similar it looks. In the third scenario, check the platform's current terms before uploading. A platform requiring a non-exclusive sublicense may still be compatible with CC BY-SA. One that demands an exclusive or perpetual sublicense does not work.