All visitors to Laos must hold a passport valid for at least 6 months after the arrival date and that contains at least 2 unused visa pages.

Exemption:
Ordinary passport
- According to the maximum duration of their stay within the country, nationals of hereafter listed countries holding normal passport and entering Lao through its 4 international airports air (Vientiane, Savannakhet, Champasak and Luang Prabang) are visa exempt:
Up to 30 days:
Cambodia, Indonesia, Malaysia, Mongolia, Philippines, Russia, Singapore, South Korea, Thailand, Vietnam.
Up to 15 days:
Japan, Luxembourg, Switzerland.
Up to 14 days:
Brunei, Myanmar
- Travelers of Lao origin under 15 years of age are visa exempt for a maximum stay of 30 days.

Diplomatic and service category passports:
Up to 90 days:
Japan, Korea (Rep.), Pakistan and Serbia
Up to 30 days
Armenia, Azerbaijan, Belarus, China (People's Rep.), Cuba, Czechia, Georgia, Hungary, India, Kazakhstan, Korea (Dem. People's Rep.), Kyrgyzstan, Moldova (Rep.), Myanmar, Poland, Tajikistan, Timor-Leste, Turkmenistan, Ukraine and Uzbekistan
Up to 14 days:
Indonesia
Visa waiver agreement for diplomatic passports was signed with Turkey in November 2018 and it is yet to come into force. 


Visa on arrival:
This is a single-entry type visa, valid up to 30 days. It can be extended on site, for an additional 60 days (twice 30 days). Extension request will be applied directly at the Immigration Department of Vientiane or Luang Prabang. 
Formalities and required documents:
- Visa application form 
- One ID picture (extra $1 fee if missing)
- From 20 to 45 USD according to your country of origin
Other "administrative supplements" may also be required at the crossing certain land borders
Since the implementation of a central electronic visa service (e-visa), the Laos government is progressively restricting the delivery of visa on arrival. It is no longer accepted at Savannakhet International airport nor at the following land-border checkpoints (Complete list of Lao border checkpoints here):
- Pang Hok (Phongsaly province) border with Vietnam
- Nam Soy (Huaphanh province) border with Vietnam
- Nam Kan (Xieng Khouang province) border with Vietnam
- Nam Ngeun (Xayaboury province) border with Thailand
- Nam Heuang (Xayaboury province) border with Thailand
- Nam Phao (Khammouane province) border with Vietnam
- Na Phao (Khammouane province) border with Vietnam
- Phou Keua (Attapeu province) border with Vietnam 
- Savannakhet International Airport
- Lan Tui (Phongsaly province) border with China
- Ban Meuang Mom (Bokeo Province) border with Myanmar
- Pakxan- (Bolikhamxay Province) border with Thailand
- Phoudou  (Xayaboury province) border with Thailand
Nationals of the following countries are ineligible to obtain a visa on arrival, unless they are traveling on an official visit and are holding an official letter of guarantee issued by the Ministry of Foreign Affairs of Laos:
- Afghanistan, Algeria, Bangladesh, Burundi, Cameroon, Congo, DR Congo, Eswatini, Ghana, Guinea-Bissau, Ivory Coast, Iran, Iraq, Jordan, Lebanon, Lesotho, Liberia, Libya, Mozambique, Nauru, Niger, Nigeria, Pakistan, Senegal, Sierra Leone, South Sudan, Sudan, Suriname, Syria, Tonga, Zambia, Zimbabwe
https://immigration.gov.la


Online e-Visa:
E-Visa for Laos is available to citizens of all countries except countries whose citizens are ineligible for visa on arrival. eVisa is valid for 60 days from the date of issuance and its holders may stay for up to 30 days in Laos. eVisa costs varies depending on the country and can be issued within 3 business days.
As per January 1st, 2020, the e-visa can be used to enter the Laotian territory via five crossing points:
- Wattay international airport (Vientiane - capital), 
- Luang Prabang international airport 
- Paksé international airport (Champasack province) 
- Lao-Thai Friendship Bridge I (Vientiane - capital) and Bokeo provinces).
- Lao-Thai Friendship Bridge II (Savannakhet province)
Formalities and required documents:
- Application form to be filled in with personal information
- Scanned copy of the identity page of your passport
- One ID colour picture (light background, less than 6 months old).
- Online payment, price according to your country of origin
https://laoevisa.gov.la/
e-visa support: support@laoevisa.gov.la

Application at the consular offices of your country
Can be single or multiple entry type with different length of validity, renewable under specific conditions according to your country (see your local embassy for more info). Procedure can also be applied by mail.
When receiving your passport, make sure that the date of entry into the territory     is well mentioned, jus next to the visa. You could be fined heavily upon arrival otherwise.
Formalities and required documents:
- Application (Usually available on the Laotian embassies website of your country)
- 2 ID pictures
- A local address of residence (that of your hotel, contact us).
- Prices vary according to your country
- Processing time: from 3 to 10 working days,
Other link : https://immigration.gov.la/