MARC to Excel Converter

MARC records are excellent for library systems and terrible for quick spreadsheet work. A cataloguer may only need a clean list of titles and ISBNs, while a Koha migration team may need every item barcode, branch, call number and item type on a separate row. The MARC to Excel Converter on VWS Online is built for that practical gap. Upload a MARC21 file, choose whether you want one row per bibliographic record or one row per Koha 952 item, review the preview, and download the result as an Excel workbook or CSV file.

The converter supports common library exchange formats including binary MARC21 files such as .mrc and .marc, MARCEdit .mrk text, MRK-style .txt files, and MARCXML. It keeps repeated fields instead of silently discarding them, lets you request extra tags or subfields, and is designed to process the selected file in the browser. That makes it useful for catalog cleanup, migration preparation, reporting, audits, training, and controlled data analysis without forcing librarians to rebuild MARC records by hand in a spreadsheet.

What the MARC to Excel Converter does

The tool reads the structure of each MARC record and turns selected data into spreadsheet columns. For binary MARC21, it reads the leader, directory, field lengths and field positions before interpreting control fields, indicators and subfields. For MRK and MARCXML, it converts the source into the same internal record structure so that the final Excel logic behaves consistently regardless of the input format.

Default bibliographic columns include the control number, ISBN, main author, title, subtitle, statement of responsibility, edition, publication place, publisher, publication year, physical description, series, subjects, added authors, language, call number, Koha record-level item type and the leader record-type code. Publication data prefers MARC 264 publication statements when present and falls back to 260 when necessary. Repeated values such as multiple 650 subject fields or multiple 700 added authors are retained in the same cell using the separator you choose.

If the default columns are not enough, add specific MARC fields such as 020$z, 245$c, 500$a, 505$a, 942$c or 952$g. You can also enter a whole field such as 245; the converter then keeps its indicators and subfield codes in a MARC-style value rather than pretending the field is a single plain-text string.

Bibliographic rows versus Koha item rows

The most important choice is the output mode. In Bibliographic rows mode, one MARC record becomes one spreadsheet row. This is the right view when you are checking title-level metadata, building a reading list, reviewing ISBNs, comparing publishers, studying subject headings, or preparing a catalog cleanup sheet.

In Koha item rows mode, every occurrence of MARC21 field 952 becomes a separate spreadsheet row. Shared title-level information is repeated on each item row, while the 952 values stay tied to their own copy. If one bibliographic record has three 952 fields, the output has three item rows. The barcode from the first 952 is never combined with the branch or call number from the second 952.

This behavior matters because Koha uses MARC21 field 952 for item or holding information. The official Koha cataloging manual documents 952 as the location and item information field for MARC21 installations. Common subfields include 952$a for the home library, 952$b for the holding library, 952$o for the full call number, 952$p for the barcode and 952$y for the item type. The converter exposes these and other useful 952 subfields as separate columns in item mode.

Supported MARC formats

Binary MARC21: MRC and MARC files

Binary MARC21 uses the ISO 2709 record structure. The converter reads the leader and directory to locate each variable field, then separates indicators and subfields. This is the format commonly produced by library systems and MARC-aware utilities. The Library of Congress MARC 21 Format for Bibliographic Data is the primary reference for bibliographic tags, indicators and subfield definitions.

Character encoding requires special care. Modern MARC21 files may identify UTF-8 in the leader, while older files can contain MARC-8. This browser converter intentionally does not guess at non-ASCII legacy MARC-8 characters. If such data is detected, the conversion stops with a clear message so names and multilingual text are not silently damaged. Convert that source to UTF-8 with MARCEdit or another MARC-aware program, then run the UTF-8 file through this tool.

MARCEdit MRK and MRK-style text

MRK is useful because the MARC structure is readable as text. A line such as =245 10$aExample title$bSubtitle still contains the tag, indicators and subfields, but it can be inspected without a binary editor. The converter recognizes records beginning with =LDR, reads control and data fields, keeps repeated fields, and converts blank indicator backslashes to actual blank indicators internally.

MARCXML

MARCXML represents leaders, control fields, data fields, indicators and subfields as XML elements. The converter reads standard MARCXML record structures, including namespaced documents. Because XML is already Unicode-oriented, MARCXML is often a convenient format when multilingual text must survive a migration or data-review workflow.

How to convert MARC to Excel

1. Export a small representative MARC file. If you are working with Koha, start with five to ten records that include the kinds of items and repeated fields you expect in the full database.
2. Upload the MARC file. Choose an MRC, MARC, MRK, TXT, XML or MARCXML file. The converter detects the supported format from the extension and content.
3. Select the output mode. Use bibliographic rows for one row per record, or Koha item rows when every 952 holding needs its own row.
4. Choose the repeated-value separator. A pipe is a good default because commas already appear naturally inside names, notes and publication statements. Semicolons and in-cell new lines are also available.
5. Add optional MARC fields. Enter one field or subfield per line when you need data outside the standard columns.
6. Convert and inspect the preview. The page reports the detected input format, MARC record count, number of 952 item fields, output row count and column count, then displays the first 25 spreadsheet rows.
7. Download XLSX or CSV. The Excel workbook includes a MARC Data sheet plus a Conversion Info sheet. CSV is exported with UTF-8 encoding for practical spreadsheet compatibility.

How repeated MARC fields are handled

MARC is repeatable by design. A book can have several subject headings, added authors, ISBNs, notes or item records. A weak converter often keeps only the first matching value or overwrites earlier occurrences. This tool collects repeated values and preserves them in the output.

For example, three 650$a subject headings can appear in one bibliographic cell as Libraries | Cataloging | Information science. If you select a new-line separator, those values remain in one Excel cell on separate lines. In Koha item mode, repeated 952 fields are different: they are not merged into one cell. Each entire 952 occurrence becomes its own row so item-specific subfields remain associated with the correct copy.

Publication data and MARC 264 versus 260

Modern MARC21 records commonly use field 264 for production, publication, distribution, manufacture and copyright information. Older records often use 260. The converter looks for publication-oriented 264 fields first and then uses 260 when a usable 264 statement is not present. It extracts place from subfield $a, publisher from $b and date from $c.

This is a convenience for spreadsheet reporting, not a replacement for cataloguing interpretation. Field 264 is repeatable and its indicators distinguish publication from production, distribution, manufacture and copyright functions. If your project needs the exact original statement rather than a simplified publisher/date column, add 264 or its required subfields as custom output columns and review the source record.

Practical uses for librarians and migration teams

• Koha inventory review: export each 952 item to Excel and filter by home library, holding library, item type, collection code, barcode or call number.
• Duplicate and missing-data checks: sort or filter spreadsheets to find blank ISBNs, titles, barcodes, item types or branch codes.
• Migration mapping: compare legacy MARC values with the columns required by another ILS, repository or cleanup process.
• Catalog cleanup: review repeated subjects, publisher statements, language codes and local fields in a format that non-MARC specialists can understand.
• Training: show staff how MARC tags and subfields translate into ordinary data columns without editing the production catalog.
• Reporting: build one-off lists from MARC exports when the source system does not provide the exact report you need.

Privacy and browser-side processing

The MARC-to-spreadsheet conversion is designed to run in the visitor's browser. The selected source file is read locally by JavaScript and is not intentionally posted to the VWS Online server for conversion. Excel generation also happens in the browser. This is useful for library workflows because bibliographic files can contain local notes, accession data, acquisition values and other operational information that does not need to leave the user's device just to be rearranged into columns.

Privacy-first processing is not the same as permission to use sensitive data casually. Avoid putting confidential patron information into a bibliographic conversion workflow, keep original exports in protected storage, and use sanitized samples when asking someone outside your organization to troubleshoot a problem.

Accuracy checks before using the spreadsheet

A successful download only proves that the source file could be parsed and converted. It does not prove that every MARC value follows your cataloguing policy or Koha framework. Before using the spreadsheet for a production migration or bulk cleanup, compare several rows against the original MARC record and the target system.

• Confirm that 001 control numbers match the correct records.
• Check several 245 title and 100/110/111 main-entry values.
• Compare repeated 650 and 700 fields with the MARC source.
• In Koha item mode, verify that each 952$p barcode stays with its own 952$a, 952$b, 952$o and 952$y values.
• Inspect accented, Arabic, Urdu, Persian, Chinese and other non-ASCII text carefully.
• Do not assume a spreadsheet is immediately suitable for re-import. Import mappings and local frameworks can require different field structures.

If you plan to import data back into Koha after editing it, use the Excel to MARC Converter for Koha Libraries for the reverse workflow, but test a small sample first. You can also run MARC text through the MARC21 Validator and use the Koha MARC Import Validator before a production import. For building a single record from scratch, see the MARC21 Record Builder.

MARC to Excel versus Excel to MARC

These two conversions solve different problems. MARC to Excel is mainly an extraction and review workflow: structured MARC records become flat rows that are easy to filter, audit and share. Excel to MARC is a record-construction workflow: spreadsheet columns must be mapped back into valid MARC tags, indicators and subfields. A spreadsheet can lose some of the richness of the original record, so a round trip from MARC to Excel and back to MARC should never be assumed to be lossless unless you deliberately export and preserve every field needed by your project.

For a Koha migration, a safer pattern is to keep the original MARC export unchanged, create a working spreadsheet for review, document every transformation, generate a small MARC test batch, validate it, and only then scale up. The Koha Migration Readiness Checker can help you review the wider preparation work around branches, item types, patron data, backups and test imports.

Frequently asked questions about MARC to Excel conversion

Can I export each Koha 952 item as a separate Excel row?

Yes. Choose Koha item rows and the converter creates one spreadsheet row for every 952 field while repeating the shared bibliographic columns for that item. Records with no 952 field are omitted from item-row output and reported in the conversion notes.

Which MARC file formats can this converter read?

It supports binary MARC21 files such as MRC or MARC, MARCEdit MRK text, MRK-style TXT files, and MARCXML XML files. The tool detects the supported source format before parsing the records.

Does the MARC to Excel Converter upload my records?

The converter processes the selected MARC file in the browser. The tool does not intentionally upload the source MARC file to VWS Online for conversion. Normal website requests and third-party infrastructure used to deliver the page are separate from the local file-conversion operation.

What happens if my binary MARC file uses legacy MARC-8?

ASCII-only legacy records can be read, but if non-ASCII MARC-8 characters are detected the converter stops and asks you to convert the file to UTF-8 first. This is intentional: displaying guessed characters would be worse than clearly telling you that a MARC-aware encoding conversion is required.

Can I export MARC fields that are not in the default columns?

Yes. Enter additional fields or subfields such as 020$z, 245$c, 500$a or 952$g. You can add up to 40 custom field specifications in one conversion. In item mode, a custom 952 subfield is taken from the current 952 item occurrence rather than merged across other items.

Can I edit the Excel file and import it directly back into Koha?

Not automatically. Excel is a convenient working format, but a MARC record contains structure that ordinary columns may not preserve. If you need a return import, define the mapping carefully, keep a backup of the original MARC, generate a small test batch with the Excel to MARC Converter, and validate the result against your Koha MARC framework before importing more records.

Related VWS Online library tools

Use the MARC to Excel Converter as one part of a controlled library-data workflow. For the reverse direction, open the Excel to MARC Converter for Koha Libraries. For structural checks, use the MARC21 Validator. If you need to prepare item-import data rather than full MARC bibliographic records, the Koha Item Import CSV Generator provides a more focused item workflow. For ISBN checks during cleanup, use the ISBN Validator.

Always keep the original export, work on a copy, test representative records and compare spreadsheet values with the MARC source. The value of a conversion tool is not merely producing a file; it is helping you move between formats while keeping enough structure visible to notice when something is wrong.