KnowRoaming

The next used eSIM during my 15-day stay in Turkey is the Yesim eSIM.
3GB Option for 30 days. ('Balkans-Region-Option' due to promo)

This worked fine as well.
Activation without any troubles.
In the region where I was, Turkish Riviera, I could only connect to Turk Telecom with 4G-speed. When trying manually to connect to other networks, this was not possible. Maybe that is just a local setting and may not be the case in other places in Turkey.

After using Vodafone with my previous eSIM, the now used Turk Telecom was perfectly working. The speed was roundabout the speed of Vodafone, did not feel any difference when using the internet.
Speed test as per below.

I would recommend to use the Yesim eSIM in Turkey.
Used: May 2024

Used the GoMoWorld eSIM in Turkey.
3.5GB Option for 7 days.

This worked fine.
Activation without any troubles.
In the region where I was, Turkish Riviera, I could only connect to Vodafone Turkey with 4G-speed. On Turkcell only 3G was possible. When trying manually to connect or force the phone to 4G, I got the message that no connection was possible. Maybe that is just a local setting and may not be the case in other places in Turkey.

Vodafone 4G however was workable.
Speed test as per below.

I would recommend to use the GoMoWorld eSIM for the use in Turkey.
Used: May 2024

Excellent. Used on many visits.

Mobimatter (eSimGo) 3GB 5G eSim. Worked fine in Türkiye. Good speed, no problems. Host network: Turkcell 4G. Unfortunately there was no 5G in Türkiye, so I should have selected 4G version of this SIM that was bit cheaper.
Initially (right after landing) it took a while to register in the host network, several refuses, but after that -- no problems. Also I tried this SIM in Estonia: Host networks: Telia (5G, 4G), Tele2 (4G). Worked seamless.

At first did not work and after 2 hours of trying everything I'm told in the e-mail they sent me and failing many times to connect, with frustration I deleted my eSIM (never do that) but when I informed the company, they provided a new QR code with automated connection details which worked like a charm. I'm getting 4.5G with no drops, no slowing downs etc. It is now a 5-star deal but being frustrated at first, I'm cutting 1 star and giving a 4.