--- title: What is a GEDCOM file slug: what-is-a-gedcom-file description: A plain text format for exchanging family trees. Learn how its records and pointers work, and what to check before another program imports it. tools: [inspect, gedcom-validator] difficulty: beginner time: 10 minutes lastChecked: 2026-09-06 published: 2026-09-03T10:55:00+02:00 --- # What is a GEDCOM file A GEDCOM file is a plain text format for exchanging family trees between programs. It usually ends in `.ged`. Many genealogy programs support it, but they differ in the versions and structures they accept. Use this page to read the structure and check what an export contains before importing it into another tree. ## What is in one Six illustrative lines: ``` 0 @1@ INDI 1 NAME Max /Mustermann/ 1 SEX M 1 BIRT 2 DATE 1 JAN 1980 1 FAMC @F1@ ``` A line starts with a level, can include a record identifier, then carries a tag and an optional value. The **level** is the first number. `0` starts a new record. A line at level 1 belongs to the record above it, and a line at level 2 belongs to the level 1 line above it. That is the whole nesting rule. The **tag** follows the level and any record identifier. `INDI` is an individual, `FAM` a family, `NAME` a name, `BIRT` a birth, `DATE` a date, `SOUR` a source. Standard tags depend on the GEDCOM version. A tag starting with an underscore denotes an extension. The **value**, when present, follows the tag. In `NAME Max /Mustermann/` the slashes delimit the surname. The `BIRT` line has no value; its child `DATE` supplies a detail. `@1@` is an identifier, called an xref. `@F1@` on the last line is a pointer to a family record elsewhere in the file. Family relationships use pointers between records. A pointer to an absent record can leave a relationship incomplete or cause an importer to reject the file. A file is a header, then records, then a trailer: ``` 0 HEAD 1 SOUR AHN 1 GEDC 2 VERS 5.5.1 1 CHAR UTF-8 0 @1@ INDI ... 0 TRLR ``` The header declares the producing program, GEDCOM version and, in older versions, character set. Those declarations guide a reader, but they can be missing or wrong. ## What causes the losses Three versions are in use, and they are not the same format. **5.5** dates from 1996; older exports can use ANSEL, a library character set. **5.5.1** dates from 1999 and permits UTF-8. **7.0** arrived in 2021, requires UTF-8, changes text continuation and adds a schema mechanism for extension tags. Check which version your destination accepts before converting. Programs also add extension tags, such as `_APID` for citation identifiers and `_UID` for record identifiers. Their meanings and supported forms depend on the producer. An importer may map an extension, retain it or drop it. After an import, compare people and family links as well as sources, notes, media links and custom events. A successful upload does not prove that the destination retained those details. ```mermaid flowchart TD P["Your genealogy program"] --> E["Export as GEDCOM"] E --> H["Header: version, producer, charset"] E --> R["Records: INDI, FAM, SOUR, NOTE, OBJE"] E --> X["Extension tags: _APID, _UID, and the rest"] H --> I["Another program imports it"] R --> I X --> D{"Does the importer know this tag?"} D -- "yes" --> I D -- "no" --> L["May retain or drop it. Check the imported result"] ``` ## The steps Numbers below are from `fixtures/public/Musterstammbaum.ged`. 1. Open [File Inspector](/inspect) and drop your file. It parses in your browser; the file does not leave your machine. 2. Read **Header**. On this fixture **GEDCOM version** reads `5.5.1`, **Producer** reads `AHN (Ahnenblatt) 2.99g`, **Declared charset** reads `UTF-8`, **Decoded as** reads `utf-8 with BOM` and **Line endings** reads `LF`. 3. Read **Records by type**. On this fixture `INDI 20`, `FAM 11`, and `HEAD`, `SUBM` and `TRLR` at 1 each. These are level-0 record counts. Inline citations, notes and media can exist without separate `SOUR`, `NOTE` or `OBJE` records. 4. Read **Problems**. On this fixture the title reads `Problems: 0 errors, 0 warnings, 0 info`. The table covers parser and encoding findings, including informational observations. It displays the first 200 rows; the totals cover all findings. ![File Inspector reading a 7,175-byte export: the header block naming GEDCOM 5.5.1, Ahnenblatt 2.99g and UTF-8, and Records by type listing 20 INDI, 11 FAM and one each of HEAD, SUBM and TRLR.](/kb/shots/what-is-a-gedcom-file-inspector.jpg) 5. Open [GEDCOM Validator](/gedcom-validator) and drop the same file. The header line states how many rules ran and what was checked: records, individuals, families, pointers, dates and facts. 6. Read the category table. `structural` is whether the file is written correctly. `referential` is whether the pointers resolve. `logical` is whether the content can be true. `encoding` is whether the bytes match the declared charset. 7. Read the three severity counts. The validator assigns `error`, `warning` and `info` to prioritize review. An error can matter to an importer, but these labels do not predict whether a particular program will accept the file. ## What to check when it worked - **Header** names the expected GEDCOM version. `unknown` can mean a missing, malformed or unsupported version declaration. - The `INDI` count matches the size of the tree you exported. - **Problems** in File Inspector is empty, or holds only `info` rows. - Review errors under `structural` and `referential`, then test the output in a separate destination tree. Passing these checks does not guarantee import support. - The producer line matches the expected exporter. Treat an unexpected value as a clue to investigate, not proof of the file's history. ## What to do when it did not **The version reads `unknown`.** Check `HEAD.GEDC.VERS` for a missing, malformed or unsupported value. [GEDCOM error messages, decoded](/how-to/decode-gedcom-error-messages) covers header checks. **The counts are far below what you exported.** Check export filters, selected branches and the sender's expected counts. Truncation or malformed record starts can also reduce the count. The parser continues through malformed input; a low count alone does not establish the cause. **You want to assess a destination.** [Which of your custom tags each site will delete](/how-to/what-each-site-deletes-from-your-gedcom) applies dated compatibility rules to your file. Confirm the result with a test import; the report does not run the destination's importer. **Your file is 7.0 and you want another conformance check.** The external [js-gedcom checker](https://gedcom7code.github.io/js-gedcom/) offers an additional check. Review its documentation and privacy behavior before loading a private tree. **You want to open it and read it, not audit it.** [Read a GEDCOM without installing anything](/how-to/read-a-gedcom-without-installing-anything) is the shorter path. ## Related - Pillar: [how to work out what a GEDCOM file actually contains](/how-to/work-out-what-a-gedcom-file-actually-contains) - Sibling: [read a GEDCOM without installing anything](/how-to/read-a-gedcom-without-installing-anything) - [How to convert GEDCOM 5.5.1 to 7.0, and what does not survive](/how-to/convert-gedcom-5-5-1-to-7-0-and-what-does-not-survive) - [What is ANSEL, and why your names look wrong](/how-to/what-is-ansel-and-why-your-names-look-wrong)