DOCUMENT FIDELITY TEST

What happens to a DOCX after a round trip?

We created a sample DOCX containing a range of document structures, processed the same file in Microsoft Word and Thinkfree Office, and compared the resulting DOCX and PDF files.

SINGLE TEST DOCUMENT · DOCX + PDF · AUGUST 2026

Visual comparison

Visual comparison is only the first check. We also compared the structure of the resulting DOCX files and the layout of the exported PDFs.

Microsoft Word

DOCX sample document opened in Microsoft Word for fidelity comparison.

Thinkfree Document Editor SDK

same page, same zoom

Round-trip results

The same source DOCX was processed in Microsoft Word and Thinkfree Office. We then analyzed the resulting document packages and compared the structures present in this sample.

Results below apply to this sample document.

19 / 19

OOXML parts preserved

All 19 OOXML parts checked in this sample remained present after the round trip.

16 / 16

Construct counts unchanged

Counts for merged cells, cell borders, section breaks, page-number fields, and body text remained unchanged in this sample.

1

Difference found

One difference in the round trip.

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ConstructOOXMLInputOutputResult
Footnoteword/footnotes.xml11Identical
Embedded chartword/charts/chart1.xml3 series3 series27 / 27 values
Row mergew:vMerge44Identical
Column mergew:gridSpan11Identical
PAGE fieldw:fldChar + w:instrText22Still a field
Headers / footersheader1–3, footer1–33 + 33 + 3Identical
Cell borders / shadingw:tcBorders, w:shd66 / 666 / 6Identical
Fixed table layoutw:tblLayout, w:tcW1 / 331 / 33Identical
Section breaksw:sectPr22Identical
Body textw:t runs4141Byte-identical
List definitionsw:abstractNum, w:num2 / 31 / 1Consolidated

WHAT CHANGED

List definitions were consolidated.

The input contained two abstract list definitions and three list instances. The resulting document contained one abstract definition and one list instance. The visible bullet formatting remained unchanged in this sample.

How closely did the exported PDFs match?

We also exported the same sample from Microsoft Word and Thinkfree Document SDK and compared the resulting PDFs.

49 / 50

text runs within 0.5pt

In this sample.

0.09pt

vertical offset standard deviation

Across matching text runs in this sample.

A small number of export differences were also observed in this sample.

TEST METHODOLOGY

How this comparison was made

A synthetic DOCX sample containing a range of document structures was created for this comparison. The same source file was opened and processed in Microsoft Word and Thinkfree Document SDK. The resulting DOCX files and PDFs were then analyzed and compared.

The sample and resulting files were analyzed with Claude. These results describe this test document only and should not be read as a general fidelity benchmark across all DOCX files or features.

What this sample doesn’t cover

Hyperlinks, raster images, tracked changes, comments, text boxes, CJK line breaking, and more complex ordered-list behavior were outside the scope of this sample.

SAMPLE DOCUMENT

Inspect the sample yourself

Download the source and resulting files used in this comparison and inspect them directly.