International Genealogical Index

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The International Genealogical Index (IGI) is a computer file created by The Church of Jesus Christ of Latter-day Saints. It was first published in 1973 and continued to grow through December 2008. It contains several hundred million entries, each recording one event, such as a birth, baptism (christening), marriage, or death.

Information in the IGI came from two sources:

1.  Some of the entries in the IGI were indexed by the genealogical community from collections of vital and church records (approx. 460 million names). Indexed records are valuable sources of primary information. Unfortunately, attempts to prevent duplication resulted in the exclusion of some indexed records.

2.  Some of the information in the IGI was contributed by members of the Church about their ancestors (approx. 430 million names). The quality of this information varies. Duplicate entries and inconsistent information are common. Always verify contributed entries against sources of primary information.

Accessing the International Genealogical Index

Over the years, access to the IGI has advanced with technology. First available on microfiche, the IGI was subsequently available on compact disc and later as a collection on the Internet.

Today, FamilySearch publishes hundreds of collections of vital and church records for many locations throughout the world. Indexed entries from the IGI are treated consistently with other indexed records, published by country or state and organized into the record collections they were trasncribed from.

Performing a regular search on will search both IGI indexed records along with billions of more recently indexed records. To search just the entries from the International Genealogical Index, select the “International Genealogical Index (IGI)” collection from the list of historical record collections. From the collection page you may choose to search either community indexed entries or community contributed entries.


The International Genealogical Index is a finding aid. Always check original sources. Entries often do not contain all the information in the original records, such as death dates or names of additional relatives. Sometimes only portions of parish records or other sources were indexed.

Today’s implementation of the International Genealogical Index addresses key deficiencies in the previous implementation. However, it is not able to correct all of them.

1.  Previously, the IGI could not be searched by city or parish name, but only by country and one subdivision (such as U.S. state or U.K. county). Users compensated by searching by batch number. While batch number searching is still supported, most users will prefer searching by name instead of number.

2.  Previously, indexed entries and community contributed entries were mixed into a single collection. The reliability of the two is different, so users needed to know the source of each result. Users compensated by examining the first digit of the batch number of each result. Batch number charts assisted users in recognizing indexed (“extracted”) entries and user contributed entries. Today, the two types are searched separately, assisting users to distinguish between them.

3.  While it grew to contain a tremendous amount of duplication, the IGI was originally envisioned as a file containing just one entry for each birth and each marriage that has ever occurred. When new records were indexed, entries were discarded that duplicated existing IGI entries. To compensate for this limitation, when an entry is not found among indexed entries, search the community contributed entries as well.

4.  The original sources for entries in the IGI are not shown. For an indexed entry, look up the film number in the FamilySearch or Family History Library catalog. For a community contributed entry, the contributor may or may not have specified a source. See “Finding the Source of IGI Batch Numbers” for more information.


1973   Originally published as “the Computer File Index.” Published on microfiche. Contained 20 million entries. About 80% were extracted.
1975   Microfiche edition with 34 million names.
1981   This, the 4th edition, was the first to be called the International Genealogical Index. Contained 81 million entries.
1984   Record count was 108 million. Offered for sale to the public.
1988   First published on compact disc (CD-ROM). Part of the FamilySearch DOS computer program. Contained 147 million names. Excluded some indexed entries from the 1984 edition.
1992   Microfiche edition. Contained 187 million names. About 94.5% were indexed.
March 1993   The CD-ROM edition took longer. Contained over 200 million names from over 90 countries.
July 1994   CD-ROM release of the 1994 edition issued as an addendum with 42 million entries. Includes entries dropped from the 1988 edition. Duplication rate increased over previous editions.
1997   CD-ROM addendum increased entries from 240 to 284 million, of which 100 million were from extraction.
24 May 1999   FamilySearch website released. Not all 285 million IGI entries available immediately, but were released by region.

For more information see Ancestry Insider, “When was the IGI?” The Ancestry Insider dated 4 January 2011).


Millions of records were indexed to create the International Genealogical Index. Each group of records was assigned a "batch number." To determine if records in a particular part of the world were indexed, and to identify their batch number, and provenance, see International Genealogical Index Coverage.

Further Reading

The following articles were originally written for previous versions of the International Genealogical Index and some information may no longer apply.

The following blog articles were written by the Ancestry Insider.