Thai Vehicle License Plate OCR

Reads a Thai licence plate from a photograph: the number, the province, and the vehicle's make, model, body type, colour and orientation.

Version 3.0 on the main endpoints

Since 3 October 2026 the main endpoints serve version 3.0. The …/license-plate-ocr-v3 paths remain available as aliases at the same price. Every existing field keeps its name and format, so no code changes are needed.

POST/v3/store/smart-city/license-plate-ocr

+2 endpoints

Try it

• Price0.25 ICper request
• Monthly plans from1,500THB a month
• Measured99.4%
• Capacity11,000 images/hour
• Served21.3Mcalls

• v3.0.0-20260828
• Updated 28 Aug 2026
• Active
• Benchmark paper (PDF)

Input

OutputPOST /v3/store/smart-city/license-plate-ocr

conf

93.39

country

th

lp_number

ขก5337

province

th-83:Phuket (ภูเก็ต)

vehicle_body_type

pickup

vehicle_brand

isuzu

vehicle_color

red

vehicle_model

isuzu_d-max

vehicle_orientation

315

vehicle_year

2020-present

is_vehicle

yes

is_missing_plate

no

message

success

status

200

Every field, under ResponseOther endpoints: /base64, /base64 see Request

Request

curl -X POST https://api.iapp.co.th/v3/store/smart-city/license-plate-ocr \
  -H "apikey: YOUR_API_KEY" \
  -F "file=@vehicle.jpg"

Response

200OK. The fields are explained under Response.

{
    "conf": 93.39,
    "country": "th",
    "lp_number": "ขก5337",
    "province": "th-83:Phuket (ภูเก็ต)",
    "vehicle_body_type": "pickup",
    "vehicle_brand": "isuzu",
    "vehicle_color": "red",
    "vehicle_model": "isuzu_d-max",
    "vehicle_orientation": "315",
    "vehicle_year": "2020-present",
    "is_vehicle": "yes",
    "is_missing_plate": "no",
    "message": "success",
    "status": 200
}

Monthly plans

• Gate S10,000 images a month1,500 THB a month, 0.15 THB per image
  or 15,000 THB a year, two months freeSubscribe
• Gate MMost chosen30,000 images a month3,000 THB a month, 0.1 THB per image
  or 30,000 THB a year, two months freeSubscribe
• Gate L100,000 images a month7,500 THB a month, 0.075 THB per image
  or 75,000 THB a year, two months freeSubscribe

Prices before 7% VAT. Every Licence plate recognition endpoint counts against the plan; beyond it, calls cost 0.25 credits per image from your balance, the pay-as-you-go price. Renews by card each month or year; cancel any time, effective at the end of the period.

Request

multipart/form-data, or the image as Base64 to /base64; 0.25 IC per request on every endpoint. For a gate that reads every day, a monthly plan costs less: Gate S 1,500 THB for 10,000 images, Gate M 3,000 THB for 30,000, Gate L 7,500 THB for 100,000 (before VAT; images beyond a plan are 0.25 IC each).

Headers

apikeystringrequired

Your API key, created under API Keys in the control panel.

Body

filefilerequired

The photograph. JPEG or PNG, up to 2 MB. On /base64, send JSON {"image": "<base64>"} instead.

Endpoint	Engine
/v3/store/smart-city/license-plate-ocr, …/base64	3.0 since 3 October 2026 (2.0 before)
/v3/store/smart-city/license-plate-ocr-v3, …/base64	3.0, alias of the main endpoints

The legacy paths /iapp_license_plate_recognition_v1_file, …_v1_base64, /license-plate-recognition/file and …/base64 follow the main endpoints at the same price.

Response

As in the panel, from both engines:

lp_numberprovincecountry

The plate, the province as th-83:Phuket (ภูเก็ต), and the country: th, my, mm, la

confnumber

Confidence in the plate reading, in percent

vehicle_brandvehicle_modelvehicle_year

Lowercase slugs, isuzu and isuzu_d-max, and the model's year range

vehicle_body_typevehicle_colorvehicle_orientation

sedan, pickup, suv and so on; the colour; the angle in degrees

is_vehicleis_missing_plate

yes or no

messagestatus

success, and the HTTP status

Version 3.0 adds vehicle_make_model_slug and make_model_conf, 0 to 1; vehicle_make_model_topk, the top five candidates with probabilities; vehicle_logo_brand and logo_brand_conf, the brand read independently from the badge and grille; vehicle_fuel_type: EV, Hybrid, Plug-in Hybrid, Petrol, Diesel, or multiple when the model is sold with several, listed in vehicle_fuel_options; and country_support_level: production, beta or detection_only.

Details

Measured

853 held-out images of today's Thai traffic covering all 73 models, never used in training; both engines read the same images. Method and per-model results: the benchmark paper (PDF).

Measure	Previous engine, v2.0, 2023 catalogue	Version 3.0
Brand correct	38.5%	99.4%
Brand correct, models within the v2.0 catalogue	41.8%	99.3%
Make and model correct, top-1	10.4%	99.18%
Make and model within top-5	—	100.0%
Returns an answer	about 50%	100%
Median time	0.2 s per image	0.5 s per image
Sustained throughput	—	11,000 images per hour at concurrency 4, production, 28 Aug 2026

310 of the 853 images, 27 of the 73 models, are vehicles introduced after the 2.0 catalogue was built, which 2.0 cannot identify by design. Plate, province, colour and orientation reading are unchanged; 3.0 is deterministic, the same vehicle giving the same answer on every scan, tight grille close-ups from gate cameras included.

Limits

• Neighbouring countries: Malaysia in production, Myanmar in beta, Laos detection only.
• Fuel type comes from the identified model through a maintained table, never from the image.

Data handling

Images are processed in memory and not kept after the response; no image goes to an external service. Consent and notice under PDPA and GDPR remain with you as the data controller. For an on-premise deployment, in which no photograph leaves your network, contact us.

Changelog

Version	Date	Changes
3.0.0	3 Oct 2026	The main endpoints move from version 2.0 to 3.0; the -v3 paths remain as aliases.
3.0.0	28 Aug 2026	New make and model engine covering 73 models across 17 brands, with no API changes; adds fuel type, confidence scores, logo verification and neighbouring countries' plates; served first on the -v3 endpoints.
2.0	16 Feb 2023	Added body type, year range, orientation, is_vehicle and is_missing_plate.
1.2	16 Jan 2023	92.28% exact match overall on the 100-image evaluation set.
1.1	23 Dec 2021	86.49% exact match overall on the 118-image evaluation set.
1.0	12 Sep 2021	First release: plate, vehicle type, brand, colour, province.