Navigate Sukhumvit's endless sois and find where locals eat real Thai food, not tourist pad thai.
Sukhumvit is a 15km strip with hundreds of restaurants in side sois (alleys); each soi has its own vibe, price range, and specialty.
Soi 38–41: backpacker street food clusters, 30–100 THB; Soi 33–37: mix of street food and shophouses, 50–150 THB.
Soi 20–25: local workers eat here, good quality, 60–200 THB; Soi 26–31: mix of Thai and international.
Soi 11–19: trendy restaurants, cocktail bars, fusion dining, 300–800 THB.
Go to where you see Thai office workers eating (lunch time), avoid glowing signs advertising 'local favorites' to tourists.
Lunchtime sois fill fast between 11:30 AM and 1 PM as office workers pour out; evening sois pick up from 6 PM onward as commuters head home via the BTS.
Pointing at what another table is eating works fine almost everywhere; a few basic Thai food words help but aren't essential given how visual most stalls' offerings are.
Pick one soi and walk it end to end rather than trying to sample the whole strip in one evening — Sukhumvit's scale rewards focus over an ambitious multi-soi crawl.