XLS to ODS Converter

What is XLS to ODS Conversion?

XLS to ODS conversion is the process of transforming a spreadsheet from the legacy binary Microsoft Excel 97-2003 format into the open OpenDocument Spreadsheet standard. This is an upgrade from a closed proprietary format to an open international standard, often associated with an organization's transition from Microsoft Office to free alternatives or with a desire to ensure long-term data preservation.

The XLS (Excel Spreadsheet) format is a binary BIFF (Binary Interchange File Format) developed by Microsoft in the late 1990s. It was the main spreadsheet format of Excel from version 97 through version 2003 - nearly 10 years. XLS is a closed proprietary format with a binary structure that was poorly documented until 2008.

The ODS (OpenDocument Spreadsheet) format is part of the OpenDocument Format (ODF) family - an open standard approved by the International Organization for Standardization as ISO/IEC 26300. An ODS file is technically a ZIP archive containing XML documents that describe sheets, cells, formulas, styling, charts, and metadata. ODS is the native format for open-source spreadsheet software and is used as one of the main formats in Google Sheets.

PEREFILE performs XLS to ODS conversion by transferring all spreadsheet elements from the binary format to the open XML format while preserving structure, formulas, formatting, sheets, and charts.

Why Switch from XLS to ODS

Open Standard versus Proprietary

ODS is the international standard ISO/IEC 26300, whose specification is publicly available. Any program can correctly work with ODS; there is no dependence on a single vendor. XLS, in contrast, is a proprietary format historically controlled by Microsoft. Until 2008, its specification was partially closed.

Long-Term Data Preservation

Open formats are better suited for archival storage. In 20 or 50 years, when Microsoft Excel may no longer exist in the form we know, the open ODS standard will be readable because its specification is documented and available worldwide.

Transition to Free Software

If an organization is switching from paid Microsoft Office to free open-source alternatives, ODS becomes the native format. Accumulated XLS files are better converted to ODS for optimal work in the new software.

Removing XLS Limitations

XLS has strict limits: 65,536 rows, 256 columns, a limited palette of 56 colors, sheet names up to 31 characters. ODS does not have these limitations (or they are significantly looser), which gives more freedom.

Data Transparency

The ZIP structure of ODS can be opened in any archive utility and the XML files inside can be viewed. This allows data extraction programmatically without specialized binary parsers. Binary XLS requires complex libraries for reading.

Compatibility with Modern Systems

Modern programs and web services increasingly support ODS as one of the main formats. Google Sheets opens ODS natively. Open office suites use ODS by default. Many government systems are transitioning to ODF.

Comparing the XLS and ODS Formats

These formats represent different eras and approaches to spreadsheet documents:

The key architectural difference: XLS is a monolithic binary file, ODS is a structured archive of open XML files. This gives ODS advantages in transparency, reliability, and long-term preservation.

When XLS to ODS Conversion is Needed

Organizational Transition to an Open Office Suite

With a corporate decision to abandon paid Microsoft Office in favor of free alternatives, XLS files accumulated over years need to be converted to ODS - the native format of open-source spreadsheet software. This provides optimal work in the new software.

Moving Away from Closed Proprietary Formats

Government agencies, educational institutions, and public organizations often switch to open standards for political or ethical reasons. ODS is an ISO standard that meets requirements for open formats.

Preparing for Long-Term Archival Storage

For archives, corporate memory, and historical data, open formats are preferable: they are guaranteed to be readable in the future. Translating XLS archives to ODS is part of a digital preservation strategy.

Using Google Sheets

Although Google Sheets opens both XLS and ODS, working with ODS goes more smoothly: fewer compatibility warnings, better transfer of specific elements.

Collaboration in a Mixed Environment

If the team uses different office suites (some Excel, some open spreadsheet software), ODS may be a convenient default format: both environments open it equally well.

Removing XLS Limits

If data does not fit into the 65,536 rows or 256 columns of XLS, conversion to ODS removes these limitations. ODS supports a million rows and a thousand columns.

What is Transferred During XLS to ODS Conversion

This is typically a high-quality conversion because both formats support approximately the same set of capabilities (with ODS advantages in some aspects):

Cell Data

All values - numbers, text, dates, time, logical values, formulas, errors - are transferred without losses. Basic table content is fully preserved.

Formulas with Syntax Translation

Formulas are automatically converted from Excel syntax to OpenFormula syntax (the ODS standard):

• Most standard functions have direct equivalents (SUM, IF, VLOOKUP, INDEX, MATCH)
• The sheet separator changes from an exclamation mark (Sheet1!A1) to a dot (Sheet1.A1)
• Function names are adjusted if necessary
• Relative and absolute references are preserved

Formatting

• Fonts, sizes, styles (bold, italic, underline)
• Text and fill colors (with extension to full RGB in ODS)
• Cell borders, line types
• Alignment (horizontal, vertical, text rotation)
• Number formats (currency, percentages, dates, fractions)
• Merged cells

Multiple Sheets

All sheets from the XLS workbook are transferred to ODS preserving order. The sheet name length in ODS can be up to 127 characters, which is more than the XLS limit - names are not truncated.

Charts

Most charts are transferred. ODS uses its own chart rendering engine, so slight visual differences are possible. Standard types (bar, line, pie) transfer well.

Images

Images and illustrations embedded in sheets are transferred to ODS.

Conditional Formatting

Conditional formatting rules (cell highlighting based on conditions) are converted. Simple rules transfer transparently; complex ones may require visual verification.

Technical Aspects of the Conversion

Translating Formulas from Excel to OpenFormula

Excel uses its own formula syntax that has historically evolved since the 1980s. OpenFormula is a standard defined in ODF, more modern and systematized. Fortunately, these systems are largely compatible:

• Most standard functions (mathematical, logical, statistical, text) have the same names
• Reference syntax differs in small details that are automatically corrected
• Unique Excel functions without OpenFormula equivalents may require manual replacement - such cases are rare

Color Palette Matching

XLS uses a limited palette of 56 preset colors. ODS supports the full RGB spectrum. During conversion, XLS colors are mapped to their exact RGB equivalents, which usually happens without visual losses.

Expanded Capabilities

Conversion to ODS opens up capabilities that XLS did not have:

• You can add more rows and columns
• You can use the full color palette
• You can give sheets more descriptive long names
• You can use new types of formatting supported by ODS

Metadata

Author, creation date, modification date, title, keywords - all document metadata is transferred to the new ODS file.

Which XLS Files Convert Well

Standard Office Tables

Budgets, reports, price lists, registries, databases, financial models with standard formulas - all convert to ODS without losses.

Multi-Sheet Workbooks

Workbooks with multiple sheets and linked formulas transfer with quality. A bonus - in ODS you can give sheets more meaningful long names.

Documents with Standard Charts

Regular charts (bar, line, pie, scatter) transfer well. Complex combined charts may require visual verification.

What May Cause Difficulties

• Files with VBA macros - VBA does not work in open office suites. After conversion, macros need to be rewritten in the built-in Basic language of the target suite
• Documents with very specific Excel functions without direct OpenFormula equivalents
• Complex pivot tables - may require verification and refinement
• Files with Excel add-ins (Power Query, Power Pivot) - functionality may not transfer

Advantages of the ODS Format

Openness and Longevity

ODS is the ISO/IEC 26300 standard; its specification is available to all. This guarantees that ODS files will be readable decades from now regardless of the fate of specific programs.

Smaller File Size

The ZIP compression used in ODS significantly reduces file size compared to binary XLS. Large tables in ODS take 30-50% less space.

Better Corruption Resistance

If an XLS file is damaged, recovering data from it is difficult. ODS is an archive of XML files; if damaged, part of the content can be extracted by opening the ZIP in an archive utility and working with XML directly.

Structural Transparency

ODS content can be studied by simply opening the ZIP archive. This is convenient for debugging, data migration, and programmatic analysis without specialized libraries.

Removing XLS Limits

• A million rows versus 65,536 in XLS
• A thousand columns versus 256 in XLS
• 127-character sheet names versus 31 in XLS
• Full RGB versus 56-color palette in XLS

Compatibility with Modern Software

ODS opens in open-source spreadsheet programs, Google Sheets, Microsoft Excel 2007 and newer (with some limitations), WPS Office, Numbers, and other programs.

Limitations and Recommendations

VBA Macros

If XLS has VBA macros, after conversion they will not work. Open spreadsheet programs use the built-in Basic language with a different object model. Macros need to be rewritten. If automation is critical, allow time for this work.

Unique Excel Functions

Some functions specific to Excel (new data types, Power Query functions) may not transfer. Check formulas after conversion - if there are #NAME? errors, replace functions with standard equivalents.

Complex Charts

Very complex combined charts may look slightly different after conversion due to different rendering engines. Standard charts transfer without problems.

Compatibility with Microsoft Office

Although modern Excel can open ODS, for optimal work with such files it is better to use the native open-source office suites. Excel may show compatibility warnings.

Alternatives to Online Conversion

Using Desktop Spreadsheet Editors

If you have a free open-source office suite or Microsoft Excel 2007+ installed, you can open XLS and save as ODS via the "Save As" dialog. The downside is the need to install the program.

PEREFILE Online Service

• No software installation required - conversion is performed in the browser
• Quality processing of formulas, formatting, sheets
• Suitable for one-time conversions and regular migration
• Available from any device with internet

Who Benefits from XLS to ODS Conversion

Employees Transitioning to an Open Office Suite

Corporate migration from Microsoft Office to free open-source office suites involves converting accumulated XLS files to ODS. This provides optimal work with files in the new software.

Government Employees

Government agencies in many countries are switching to open formats. Many jurisdictions include ODF in the list of recommended formats for government systems. Translating documents to ODS is part of this migration.

Workers at Budget-Constrained Organizations and NGOs

Institutions with limited budgets often abandon paid Microsoft Office in favor of free alternatives. Conversion of historical XLS files to ODS facilitates the transition.

Archivists and Museum Workers

Digital archives are better stored in open formats. ODS is a reliable choice for long-term preservation of tabular data.

Educational Institutions

Schools and universities switching to free software for budget savings need to convert educational materials and templates from XLS to ODS.

Open Software Advocates

Users who refuse proprietary software on principle translate their data to open formats. ODS is the right choice for tabular data.

After Conversion: What to Do with ODS

Open in a Free Open-Source Office Suite

Such programs use ODS as the native format and provide the best work with such files. Download for free from official websites, install, open files with a double click.

Use Google Sheets

Upload ODS to Google Drive - it will open in Google Sheets. You can edit online, share links, and collaborate.

Check Formulas

After opening, check whether there are #NAME? errors in cells with formulas. If there are, it means functions were used that have no OpenFormula equivalents. Replace them with standard equivalents.

Rewrite Macros

If the source XLS had macros, they need to be rewritten in the built-in Basic language of the target suite. This is a separate task requiring knowledge of both languages.

Use in Modern Systems

ODS can be uploaded to government systems requiring open formats, shared with users of open office suites, and sent to document management systems supporting ODF.