Some additional points to what Matthias already said in the same thread.
The main differences are lower price and latency while having roughly the same (or sometime superior) quality.
In terms of price Keenable is 4$ per 1000 queries, and for each query you can have up to 50 results for the same price. Exa charges 7$ per 1000 queries, and charges additionally for each result that is out of top-10. Parallel charges 5$ per 1000 queries.
In terms of latency, Keenable is much faster than both Exa and Parallel, especially in the "realtime" mode. p50 is less than 200ms.
The main differences are lower price and latency while having roughly the same (or sometime superior) quality.
In terms of price Keenable is 4$ per 1000 queries, and for each query you can have up to 50 results for the same price. Exa charges 7$ per 1000 queries, and charges additionally for each result that is out of top-10. Parallel charges 5$ per 1000 queries.
In terms of latency, Keenable is much faster than both Exa and Parallel, especially in the "realtime" mode. p50 is less than 200ms.
As for the quality, you can also check the AA analysis: https://artificialanalysis.ai/agents/search-api