The first thing you should know about eating vegan in Krabi Town is street food! Other than Bangkok and Chiang Mai, we found Krabi Town to have the most Thai street food options. There are many different night markets, food stalls, and walking streets which feature many vegan options: mainly steamed vegetables.
SO MANY MANGOES at Krabi Town's main fruit market
We became friends with this lovely lady who operated a steamed veggie cart. We came to her all three nights we were in Krabi Town - it was delicious! She offered steamed mini sweet potatoes, water chesnuts, corn, pumpkin and even steamed banana! She was located on the main Maharajah road near the large 7/11, right at the top of the Night Market street.
The offerings of the awesome food cart lady near the Night Market
Steamed pumpkin with coconut shreds - great, inexpensive street food in Krabi Town
More Krabi Town street food - fresh young coconut, steamed corn, and mango and sticky rice
The next place you must try is 31 Restaurant Chaofah Road. We went here a couple of times because it was located right next to our hostel in Krabi Town. Though 31 Restaurant is not all-vegan, they serve up some delicious vegan options. The owner is well-aware of the concept of veganism, and even got a little angry when we wanted to confirm vegan meant no eggs, dairy, fish sauce, etc., replying "I get it, I get it, I know what you mean, enough". My personal favourite has to be the pineapple curry with tofu - it was one of the best meals I had in Thailand. The vegan pad thai is also worth a try. Relatively cheap prices.
Pineapple and tofu coconut-milk curry (and pad thai in the background!) at 31 Restaurant in Krabi Town
And lastly, I highly recommend Hong Ming Vegetarian Food. This is an all-vegan restaurant in Krabi Town and it is very, very inexpensive! We ate here three times during our three days in Krabi Town. You can opt to order a Thai soup or pick three to five options from the hot foods of the day. It is a lot of fake meats, which are very convincing, but they usually have a great vegetable curry ready to serve. We never ended up spending more then 90 baht (around $3) in total for the two of us - so it's very affordable. Be sure to check it out!
All vegan and so many options at Hong Ming!
Hong Ming Vegetarian Food - 60 ($2) baht for the plate