🇹🇭 The best dictionaries for learning Thai

Longdo aggregates several dictionaries at once (including NECTEC's LEXiTRON and Thai–Thai sources), so a single search shows technical, colloquial and formal senses side by side. Because it is built for Thai users it covers vocabulary that learner dictionaries omit entirely, which matters once you are reading real material. The interface is cluttered and largely in Thai, so it suits intermediate learners more than day-one beginners.

A long-running community reference with a large Thai–English dictionary, audio, per-word tone and phonemic analysis, sample sentences, grammar lessons and archived forum discussions that answer questions nothing else does. It is the site experienced learners keep open in a tab. The design is unapologetically from an earlier internet era and the site serves over plain HTTP, so expect a browser warning if you force HTTPS.

Over 100 language editions; the English edition alone has millions of entries covering hundreds of languages, with IPA, declension and conjugation tables, etymologies and usage notes that commercial apps usually paywall. The etymology sections are quietly one of the best vocabulary-retention tools available. Being crowd-sourced, coverage is uneven and rare entries can be wrong — cross-check anything unusual against a native-language dictionary.

Around 6 million words recorded by native speakers across 400+ languages, usually with several accents per word so you can hear regional variation. Free to search on the site; the paid tiers are aimed at API users and bulk audio downloads. Indispensable for names, place names and anything a TTS voice would mangle — many learners wire it directly into Anki for card audio.

Thai is written without spaces between words, which makes early reading brutal; this tool segments a pasted passage and glosses each word with tone-marked transliteration and audio. That makes it the fastest way to work through a Thai post, menu or news snippet before your parsing is automatic. Core lookup is free with a paid tier for extras, and its segmentation occasionally mis-splits names and compounds, so sanity-check anything surprising.

Paiboon's app pairs a large Thai–English dictionary with human-recorded audio for essentially every headword, plus a categorised phrasebook, and it works fully offline — which is the point when you are standing in a market with no signal. Search tolerates rough spelling and transliteration, a real advantage while your reading is shaky. It is a one-off paid app on iOS, Android and Windows, and the interface looks its age.