Segovia attractions best time Cathedral & Alcazar

Visit the one you consider a must see first. Arriving early and departing later, you’ll probably have enough time to see both

We visited Segovia on a day trip from Madrid last year. We went straight for the Alcazar when we arrived as it's the furthest from the centre of town and we knew we'd probably spend the most time there. Then we walked back into town, visiting the cathedral on the way, and finishing back at the aqueduct. So I suppose we decided the order based more on geographical location than crowds, tho I would say the Alcazar was more crowded. By the way, nothing in there is labelled, but I found the wikipedia article for the Alcazar really helpful in describing what we were looking at!

We went on a Friday in late February. We took the bus from Madrid and walked to the TI by the aqueduct to rent audioguides for the city. We slowly walked to the Alcazar for our 10:30 entry. It was not crowded. There was one tour group and we moved around them. We purchased audio guides with our tickets. The only glitch was that we had to be in the ticket office to access the wifi to download the audio guide onto our phones. We did not enter the cathedral (we saw so many this trip) but enjoyed using the TI audio guide to explore the city. We had a lovely long lunch. You'll have time to see both the Cathedral and Alcazar in one day. I would do the Alcazar first, but check the cathedral website for seasonal closures.

Frankly, I would do both Toledo and Segovia over Madrid.
To me the best site in Madrid is the Prado.

I would go with the advice to do the Alcazar early to beat the crowds. It does seem to attract more people, the inside space is a series of rooms, so more likely to get crowded, or less enjoyable with a large group.

The Cathedral is relatively large, can handle a crowd, people (most anyway) stay quiet out of respect, easy to do after the Alcazar, or after lunch.

I would reserve a time for the Alcazar, not needed for the Cathedral.