General:
* Advance look: This emphasizes that it's something seen before the official release.
* Sneak peek: Similar to "advance look" but with a more informal feel.
* Glimpse: This suggests a brief look, possibly not showing the full picture.
* Pre-release: More formal and technical, emphasizing that it's a version before the final product.
* Early access: Similar to "pre-release" but implies the ability to interact with the product.
* Sampler: Often used for a short piece of music or video offering a taste of the full work.
For specific types of previews:
* Trailer (film/TV show): A short video showcasing key scenes and highlights.
* Excerpt (writing/music): A short passage or section extracted from a longer work.
* Sample (product): A small portion of a product offered for evaluation.
The best synonym for "preview" will depend on the specific context and the desired level of formality.