Admission requirements (certificates - diploma - degrees)
Anyone wanting to study at a German university needs a higher education entrance qualification (Hochschulzugangsberechtigung).The requirements for admission differ by countries, study levels and universities. As a first orientation we list some selected sources for getting a first orientation regarding the minimum requirements on secondary school level (school leaving certificates). The outlined requirements are a first orientation only concerning the academic entry requirements for admission at Pforzheim University. The minimum standards for admission are based on the recommendations for degree programs in Germany. Please note: all lists/databases are general recommendation how to handle applications; at a selected university applicants may find additional requirements (tests, interviews etc.). And of course for all study programs the applicants have to meet the respective language requirements too. Most study programs are offered in German and the applicant will have to prove sufficient German language skills; for study programs in English the applicant will have to prove sufficient language competences in English. A quick summery on language requirements your will find here.

Admission requirements
The most complete source is a database called ANABIN; it is published and supported by the Central Office for Foreign Education (Zentralstelle fuer das auslaendische Bildungswesen ZaB) of the Standing Conference of the Ministers of Education and Cultural Affairs of the Laender in the Federals Republic of Germany KMK; this database covers nearly all countries.
ANABIN Database of the ZaB

In addition to ANABIN are various other sources concerning the higher education entrance qualifications for undergraduate degree programs (Bachelor Level)
Recommendations of the Studienkolleg Konstanz
Following countries are included: Bangladesh, Brazil, Camaroon, China, Colombia, Ghana, India, Indonesia, Iran, Kenya, Morocco, Mexico, Nepal, Nigeria, Pakistan, Russia, Turkey, Ukraine and Vietnam. The list provides information about the minimum requirements for admissions based on the recommendations of the Center for International Students at Konstanz (formerly know as Auslaenderstudienkolleg) in Baden-Wuerttemberg. Please note: for admission to a university the category "direct admission" will be relevant only.

For some other countries you may find in addition the recommendations of the German Academic Exchange Service DAAD developed in cooperation with uni assist e.V.
Database of the German Academic Exchange Service DAAD and uni-assist e.V.
For the following countries you may find information in that database: Afghanistan, Brazil, Cameroon, Chile, China, Egypt, Eritrea, India, Indonesia, Iran, Iraq, Japan, Mexico, Pakistan, Poland, Romania, Russia, Singapore, South Korea, Syria, Thailand, Turkey, Ukraine, USA and Vietnam

Especially for the most relevant countries of refugees in Germany the Studienkolleg Konstanz in Baden-Wuerttemberg compiled in April 2016 a list of minimum requirements for undergraduate admission
Refugees - Recommendations for admission of the Studienkolleg Konstanz
The list includes Afghanistan, Albania, Eritrea, Iraq, Kosovo, Macedonia, Nigeria, Pakistan, Serbia and Syria.