# GEDCOM Tools Single-purpose browser tools for GEDCOM genealogy files, at https://gedcom.tools. The browser tools parse files using a Web Worker. Optional model actions send disclosed extracts through OpenRouter to a model provider after approval. Your own browser agent may also send page text or screenshots to its provider. Agree on that access before loading private data. The parser supports GEDCOM 5.5, 5.5.1 and 7.0, with ANSEL, UTF-8, UTF-16 and supported code pages. ## Preservation and review Byte-identical round trip. Reading a file and writing it straight back returns the same bytes: byte-order mark, mixed line endings, trailing spaces, long lines split across CONC and CONT, and tags no standard defines. This describes an unchanged parser round trip, not a guarantee about conversion, repair or a destination program. Review each tool's proposed edits and loss report. Keep the original. Review patches and output previews before exporting a separate file. Merge reversal needs compatible retained history; not every kind of repair has the same undo support. Supported determinations can travel in the exported GEDCOM. Other programs can remove their carriers. Verify preservation after an import/export cycle before relying on a prior decision. Review the signals, confidence and limitations a tool supplies. A score is not genealogical proof. Qualify negative searches by the sources, date ranges and coverage you checked. ## Tools ### Broken Link Repair (pro) https://gedcom.tools/broken-link-repair Finds pointers to records that do not exist, and proposes a delete, a repoint or a placeholder for each one. ### Citation Parser (pro) https://gedcom.tools/citation-parser Reads archive identifiers out of free-text citations, and proposes a structured source record for each one. ### Corrupted File Recovery (free) https://gedcom.tools/gedcom-file-recovery Rebuilds a file that other programs refuse to open, and lists every dropped byte with its offset, its hex and the reason. ### Date Normaliser (pro) https://gedcom.tools/date-normaliser Rewrites dates into the standard form across five calendars, and flags every reading the digits do not settle. ### Determination Ledger (pro) https://gedcom.tools/determination-ledger Lists every merge, verdict and negative finding written into the file, and reverts any of them. ### Dialect Report (free) https://gedcom.tools/gedcom-dialect-report Names the program that wrote the file, and warns which custom tags each of six destinations will drop. ### Duplicate Individual Finder (free) https://gedcom.tools/duplicate-finder Finds people entered twice by name, date, place and family, and tells a duplicate from a child named after a dead sibling. ### Encoding Repair (free) https://gedcom.tools/gedcom-encoding-repair Finds the character set the file was really written in, and rewrites mangled text such as "Müller" as clean UTF-8. ### File Inspector (free) https://gedcom.tools/inspect Shows the GEDCOM version, the producing program, the encoding and the record counts, with every problem the parser noticed. ### Format Converter (free) https://gedcom.tools/gedcom-converter Converts a file between GEDCOM 5.5.1 and 7.0, and lists every construct the target version cannot hold. ### GEDCOM Preflight Report (free) https://gedcom.tools/gedcom-preflight-report Runs seven import checks and downloads a self-contained HTML report of blockers, warnings and repairs without uploading the GEDCOM. ### GEDCOM Validator (free) https://gedcom.tools/gedcom-validator Checks a file for structural, referential and logical errors, and names the record, the line and the tool that fixes each one. ### GEDCOM Viewer (free) https://gedcom.tools/gedcom-viewer Opens the file as people, families, pedigrees and timelines, with every name and tag as the source wrote it. ### Impossible Fact Fixer (free) https://gedcom.tools/impossible-fact-fixer Separates dates that cannot be true from dates that are merely unusual, and proposes a reversible fix with the arithmetic. ### Link Reciprocity Checker (free) https://gedcom.tools/link-reciprocity-checker Finds family pointers the other record never answers, and sorts each into probable duplicate, orphan or incomplete entry. ### Living Person Privatiser (pro) https://gedcom.tools/living-person-privatiser Decides who is still living and redacts them, then checks the output for addresses, phone numbers and leaked names. ### Media Portability Workbench (pro) https://gedcom.tools/media-portability-workbench Finds missing media files and previews path repairs. ### Merge Conflict Arbitration (pro) https://gedcom.tools/merge-arbitration Argues both sides of one duplicate pair with a language model, which answers merge, do not merge, or not enough evidence. ### Merge Workbench (pro) https://gedcom.tools/merge-workbench Compares two people field by field, and merges them into one record as a single patch you can undo. ### Note Structurer (studio) https://gedcom.tools/note-structurer Reads the prose notes in a file, and turns the hypotheses and corrections they carry into determinations you accept one by one. ### Relationship Calculator (free) https://gedcom.tools/relationship-calculator Names the kinship between two people in both directions, and shows the parent and child steps behind the answer. ### Research Gap Planner (studio) https://gedcom.tools/research-gap-planner Finds records the tree implies but never cites, and names the archive, the parish and the year range to search. ### Subtree Extractor (free) https://gedcom.tools/subtree-extractor Extracts a standalone file around one person, ancestors or descendants to the depth you choose. ### Tree Health Score (free) https://gedcom.tools/tree-health-score Scores a tree 0 to 100 on completeness, sourcing and consistency, and lists the records that cost it points. ## How-to guides 22 articles, one problem each. Each names the tool and the control for each step, and answers at the same address with `.md` appended, as text/markdown, so an agent reads the same bytes the page was built from. ### What is a GEDCOM file https://gedcom.tools/how-to/what-is-a-gedcom-file A plain text format for exchanging family trees. Learn how its records and pointers work, and what to check before another program imports it. beginner, 10 minutes. Uses inspect, gedcom-validator. ### Read a GEDCOM without installing anything https://gedcom.tools/how-to/read-a-gedcom-without-installing-anything Someone emailed you a .ged file. Open it as people, families and a pedigree in a browser tab, with nothing uploaded and nothing installed. beginner, 10 minutes. Uses gedcom-viewer, inspect. ### How to check a GEDCOM before you import it anywhere https://gedcom.tools/how-to/check-a-gedcom-before-you-import-it-anywhere Start with a local preflight report, review structure, links, media and privacy, then check the exact file you plan to import. beginner, 30 minutes. Uses gedcom-preflight-report, inspect, gedcom-validator, gedcom-dialect-report, link-reciprocity-checker, broken-link-repair, living-person-privatiser, tree-health-score, media-portability-workbench. ### How to work out what a GEDCOM file actually contains https://gedcom.tools/how-to/work-out-what-a-gedcom-file-actually-contains Someone sent you a .ged and you have no program to open it. Read the version, the producer, the charset, the counts, the custom tags and the people, in order. beginner, 20 minutes. Uses inspect, gedcom-viewer, gedcom-dialect-report, tree-health-score, relationship-calculator. ### How to fix a GEDCOM file that will not open https://gedcom.tools/how-to/fix-a-gedcom-file-that-will-not-open Inspect an import failure, review structural recovery and its loss report, then validate the output before a test import. Keep the original export. beginner, 15 minutes. Uses inspect, gedcom-file-recovery, gedcom-validator. ### How to fix garbled characters and accents in a GEDCOM https://gedcom.tools/how-to/fix-garbled-characters-and-accents-in-a-gedcom Müller reads as Müller, or as M?ller. Compare charset detection and proposed corrections, preserve the original, and check the UTF-8 output. beginner, 15 minutes. Uses inspect, gedcom-encoding-repair, gedcom-validator. ### GEDCOM error messages, decoded https://gedcom.tools/how-to/decode-gedcom-error-messages Use an import error as a starting point. Check the file's structure, encoding and pointers before choosing a repair, and review what recovery changes. beginner, 15 minutes. Uses inspect, gedcom-file-recovery, gedcom-validator. ### What is ANSEL, and why your names look wrong https://gedcom.tools/how-to/what-is-ansel-and-why-your-names-look-wrong Your file says 1 CHAR ANSEL and the accents came out as separate marks. ANSEL puts the accent before the letter, and Unicode puts it after. intermediate, 15 minutes. Uses gedcom-encoding-repair, inspect. ### How to remove living people before sharing your family tree https://gedcom.tools/how-to/remove-living-people-before-sharing-your-family-tree Decide who is living, redact them, and check the exported file for the addresses, phone numbers and names that hide in free text. Every verdict comes with its rule. intermediate, 20 minutes. Uses inspect, living-person-privatiser, gedcom-validator. ### How to split one branch out of a large family tree https://gedcom.tools/how-to/split-one-branch-out-of-a-large-family-tree Pick a root and generation limits, review the people and references included, then validate and privatise the extracted GEDCOM before sharing. beginner, 15 minutes. Uses gedcom-viewer, subtree-extractor, gedcom-validator. ### How to prepare a GEDCOM for Ancestry, MyHeritage, FamilySearch or GEDmatch https://gedcom.tools/how-to/prepare-a-gedcom-for-ancestry-myheritage-familysearch-gedmatch Review dated compatibility warnings, protect living people's details, choose a supported GEDCOM version, and test an import before moving your tree. intermediate, 30 minutes. Uses gedcom-dialect-report, living-person-privatiser, gedcom-converter, gedcom-validator. ### How to prepare a GEDCOM for GEDmatch https://gedcom.tools/how-to/prepare-a-gedcom-for-gedmatch Prepare the branch you intend to share, redact living people's details, review privacy limits, and validate the file before a GEDmatch upload. intermediate, 25 minutes. Uses living-person-privatiser, subtree-extractor, gedcom-dialect-report. ### Which custom tags your destination may lose https://gedcom.tools/how-to/what-each-site-deletes-from-your-gedcom Compare dated compatibility warnings for six destinations. Count the custom tags at risk, check the evidence, and test what your import route preserves. intermediate, 20 minutes. Uses gedcom-dialect-report, inspect. ### How to find and fix missing media links in a GEDCOM https://gedcom.tools/how-to/find-and-fix-missing-media-links-in-a-gedcom Compare GEDCOM media paths with a folder on your device, review ambiguous matches, and download a corrected file without uploading photos. beginner, 15 minutes. Uses media-portability-workbench, gedcom-validator. ### How to find and merge duplicate people in a GEDCOM https://gedcom.tools/how-to/find-and-merge-duplicate-people-in-a-gedcom Review duplicate candidates and their evidence, merge confirmed pairs, and export the decisions and undo data. Keep a pre-merge backup. intermediate, 30 minutes. Uses duplicate-finder, merge-arbitration, merge-workbench, determination-ledger. ### How to tell a duplicate from a child named after a dead sibling https://gedcom.tools/how-to/tell-a-duplicate-from-a-child-named-after-a-dead-sibling Review same-named siblings without merging them on shared parents alone. Check the dates, sources and limits of the necronym heuristic. advanced, 25 minutes. Uses duplicate-finder, merge-arbitration, determination-ledger. ### How to undo a merge you should not have made https://gedcom.tools/how-to/undo-a-merge-you-should-not-have-made Restore a merge from its exported inverse when the data survives and still matches. Check recovery limits, preserve backups, and validate the restored records. intermediate, 15 minutes. Uses determination-ledger, merge-workbench. ### How to find every broken pointer in a GEDCOM https://gedcom.tools/how-to/find-every-broken-pointer-in-a-gedcom Find missing and wrong-type pointer targets, review delete, repoint and placeholder options, then check reciprocal family links in the repaired output. intermediate, 20 minutes. Uses gedcom-validator, broken-link-repair, link-reciprocity-checker. ### Why your dates changed when you uploaded https://gedcom.tools/how-to/why-your-dates-changed-when-you-uploaded Check numeric date order, calendar conversion and chronology findings. Review ambiguous readings against records before changing dates in your export. intermediate, 20 minutes. Uses date-normaliser, impossible-fact-fixer, gedcom-validator. ### How to turn free-text source notes into real citations https://gedcom.tools/how-to/turn-free-text-source-notes-into-real-citations Recognize supported archive identifiers, review source-record proposals, and preserve the original citation wording without treating a parsed reference as proof. advanced, 30 minutes. Uses citation-parser, note-structurer, determination-ledger. ### How to plan your next genealogy research steps https://gedcom.tools/how-to/plan-your-next-genealogy-research-steps Find gaps in your GEDCOM, review archive suggestions, and save a research plan. Use optional AI ordering without treating suggestions as evidence. intermediate, 20 minutes. Uses research-gap-planner, note-structurer, citation-parser. ### How to convert GEDCOM 5.5.1 to 7.0, and what does not survive https://gedcom.tools/how-to/convert-gedcom-5-5-1-to-7-0-and-what-does-not-survive Compare version mappings and unrepresentable structures before converting. Review extension or drop choices, validate the output and keep the original. intermediate, 20 minutes. Uses gedcom-converter, gedcom-validator, gedcom-dialect-report. ## Tool manifest https://gedcom.tools/tools.json is the same 24 tools as JSON, one object each. Every object carries what the tool needs before it runs, whether it writes a changed file or a determination, what it reports back, whether that list can be capped, suggested tool order and reasons, and the phrases a person uses when they want it. Read `data_flow` and `sends` before invoking a model. 3 of 24 tools offer a request through /api/ai/v1: Merge Conflict Arbitration, Note Structurer, Research Gap Planner. Review the payload and recipients with the owner before sending. These fields describe site behavior, not a separate browser agent's disclosure to its provider. Read `mutates` before you act. Use read-only tools within the owner's agreed scope. The flag does not authorize model requests. Review evidence, uncertainty and proposed changes before applying or exporting a changed file or determination. Preserve the original and validate each approved output. ## For agents Use the canonical Genealogy Research skill with your own agent: https://www.skills.sh/sliday/genealogy-research https://github.com/sliday/genealogy-research Read https://gedcom.tools/for-agents for skill setup, capabilities, review rules and all tool prompts. Use Copy whole page to copy that guide. https://gedcom.tools/api documents public discovery and hosted REST operations. https://gedcom.tools/mcp serves public discovery without authentication and seven authenticated hosted operations through Streamable HTTP: list_documents, upload_gedcom, get_document, analyze_gedcom, create_report, get_report and delete_document. Equivalent REST routes use /api/v1. Analysis methods are inspect_gedcom, validate_gedcom and audit_relationships; get_document returns metadata, and reports contain HTML. Hosted checks use deterministic rules, leave originals unchanged and make no paid AI calls. They do not search archives or repair GEDCOMs. Complete https://gedcom.tools/hosted-access, open https://gedcom.tools/vault and save your owner key before issuing a scoped agent key. Use Authorization: Bearer with the required read, write or delete scope. Keep owner keys out of agent configuration and credentials out of URLs and MCP tool arguments. Owner-key replacement requires a client-generated, saved replacement sent as newOwnerKey to POST /api/v1/owner-key, authenticated with the current owner key. Uploads require contentBase64 and consent: true after explicit approval for hosted retention and agent-provider disclosure. We retain private originals and reports until document or vault deletion, without training or secondary use. Returned findings can reach your agent's provider; analysis defaults to details: false. Deletion can leave storage cleanup pending. We retain up to 32 opaque uncertain-write keys and retry deletion daily, including after vault deletion, without a finite cleanup deadline. Revoking a key does not delete retained files. Per-vault quotas do not block deletion or revocation, but a global 1,000-request daily maintenance cap can delay them until UTC rollover. See https://gedcom.tools/for-agents/mcp for setup, REST routes, scopes and quotas. Archive research needs separate access through your own agent. ### Use GEDCOM Tools with your AI agent https://gedcom.tools/for-agents/overview Ask your agent to choose a browser tool, interpret a report or plan source-backed research. ### Discovery files for AI agents https://gedcom.tools/for-agents/llms Use these public files to find the right GEDCOM Tools page without loading a private tree: ### Hosted MCP and REST access https://gedcom.tools/for-agents/mcp Use remote MCP for public discovery and authenticated checks on a GEDCOM retained in your private vault. ### One prompt per tool https://gedcom.tools/for-agents/prompts Choose one of the 24 prompts and paste it into your browser-capable agent. ### Genealogy research skill https://gedcom.tools/for-agents/skill Use Sliday's canonical genealogy-research skill with your own agent.