How to fill a PDF form with OnyxPDF
- Drop the fillable PDF into the tool.
- The tool lists the form’s real fields — type your answers into them.
- Optionally tick “flatten” to bake the answers into the page.
- Click “Save” and download the completed form.
Why do it in your browser instead of uploading?
- No upload: the form you are filling — job application, visa form, tax worksheet — stays on your device.
- It uses the PDF’s real AcroForm fields, so values land exactly where the form designer intended.
- Flattening on save makes a tamper-resistant final copy: answers visible, fields no longer editable.
- Free, with no Adobe sign-in wall (Adobe’s free tools effectively require an account).
Good to know (honest limits)
- Only PDFs with real form fields can be filled this way; a scanned form image has no fields — use Edit PDF to type on top of it instead.
- Exotic field types (signature fields, barcode fields) are presented as plain inputs or skipped.
Frequently asked questions
How do I know if my PDF is fillable?
Drop it in: if the PDF has real form fields, they are listed for you to type into. If none appear, the file is a flat document or scan — use Edit PDF to place text on it instead.
What does “flatten” mean?
Flattening bakes your answers into the page content and removes the interactive fields, so the completed form cannot be casually edited afterwards. Keep an unflattened copy if you may need to change answers later.
Is my filled form uploaded?
No. Fields are read and written by JavaScript in your browser; the completed PDF downloads straight to your device.
Can I create new form fields?
Not in this tool — it fills existing fields. Creating fields is on the roadmap; the fill side covers the everyday need.