Add your FDF file
Drop one or more .fdf files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
FDF to XFDF
Converting a .fdf font to .xfdf repackages the same glyphs and metrics for a different delivery target. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop FDF files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Forms Data Format to XML Forms Data Format
Converting a .fdf font to .xfdf repackages the same glyphs and metrics for a different delivery target. An .fdf file holds the data from a PDF form without the form itself: field names and their values, stored in PDF's own object syntax, so the values can travel separately from the document and be merged back into it later.
An .xfdf file is the XML expression of PDF form data: a root <xfdf> element containing a <fields> tree in which each <field name="..."> holds a <value>. It carries the same information as FDF in a form that ordinary XML tooling can read. For this route the practical draw is plain XML, readable and processable without PDF-specific libraries and an ISO standard, unlike most of the surrounding PDF form tooling — balanced against considerably more verbose than FDF for the same data, which is worth knowing before you commit a large batch.
Why convert FDF to XFDF?
The practical trigger for this conversion is usually a mismatch: with .fdf, binary-ish PDF syntax makes it awkward to inspect or generate by hand. Switching to .xfdf buys you plain XML, readable and processable without PDF-specific libraries, which is why it is the better fit for exchanging PDF form data with web services and enterprise systems. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
FDF vs XFDF at a glance
| Aspect | Forms Data Format (.fdf) | XML Forms Data Format (.xfdf) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | the file begins with %FDF-1.x and is otherwise a normal PDF object graph, so it needs a real PDF parser rather than a text scan | root element is <xfdf> in the http://ns.adobe.com/xfdf/ namespace, with fields under a single <fields> element |
| Strongest at | extracting submitted values from a PDF form workflow | exchanging PDF form data with web services and enterprise systems |
| Weak spot | binary-ish PDF syntax makes it awkward to inspect or generate by hand | considerably more verbose than FDF for the same data |
| Metadata | the referenced-document path is detected and deliberately omitted from the output rather than carried across | the href document reference is detected and reported as omitted rather than followed or copied |
Pick XFDF as the output
Select .xfdf in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if XFDF is selectable, the route is real and validated.
Convert on your device
Press Convert. The font tables are parsed and rewritten locally with fonteditor-core; glyph outlines, hinting, and kerning survive the trip.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid XFDF file. Outputs keep the original filename with the .xfdf extension.
FDF to XFDF questions, answered
Will converting FDF to XFDF lose quality?
There is no visual quality to lose — fdf is text-oriented and xfdf is text-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Is it private to convert FDF files here?
Yes — the .fdf file is processed inside your browser tab and never uploaded. The font tables are parsed and rewritten locally with fonteditor-core; glyph outlines, hinting, and kerning survive the trip. Close the tab and the file is gone from memory.
Where will the XFDF file work?
Adobe Acrobat, PDF.js-based viewers, PDFtron, iText and most PDF SDKs read XFDF. Novus Convert parses it locally with document types, entities and external file references all blocked, and converts to FDF and JSON. Files containing submit, goto or launch actions are refused.
Will the XFDF file be bigger or smaller than my FDF?
It depends on the content: root element is <xfdf> in the http://ns.adobe.com/xfdf/ namespace, with fields under a single <fields> element. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my FDF file?
In .fdf, the referenced-document path is detected and deliberately omitted from the output rather than carried across. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.
Can I convert XFDF back to FDF?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .fdf → .xfdf → .fdf is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.