How do I fill in a PDF form online and keep or flatten the fields?
Open the PDF form in Sealique: its fields are listed in your browser; fill them, then save a copy that stays editable or is flattened, ready for a digital signature.
Application forms, declarations, registration sheets: when the PDF has real form fields, filling them in a list is quicker and cleaner than typing boxes over the page. The tool lists every field with its label, fills them on the server and lets you decide whether the next reader may still edit.
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Key facts
- Fill PDF forms on Sealique reads the fillable fields of a PDF (text, multiline, checkbox, radio, dropdown, multi-select) and lets you fill them from a phone or a computer, with an account, no card and no daily limit.
- The filled copy can stay editable, so the recipient can change it, or be flattened, so the values become part of the page.
- Read-only fields are shown but not changed; fields are filled on the server and the copy is saved in your library.
- A PDF without fillable fields is refused with a hint to use the editor, which can write on any page.
- A filled form can be sealed with a PAdES digital signature and verified online by its verification ID or QR code.
How are the fields read and written?
A fillable PDF carries an AcroForm: a list of fields with a name, a type and, for choices, the allowed options. Sealique reads that list on the server, shows it in your browser with the labels from the form, and writes the values back into the fields when you save. Flattening then draws each value onto its page and removes the field objects.
Editable or flattened: which to choose?
Keep the form editable while it moves between people who each fill a part. Flatten when the form is complete and about to be signed or archived: the PAdES digital signature then seals values that can no longer be edited, and the document can be verified online by its verification ID or QR code.
Fill PDF forms, step by step
Open Fill PDF forms
Sign in, open PDF tools and choose Fill PDF forms.
Choose the form
Drop a PDF of up to 50 MB or pick an unsigned document from your library. Its fields are listed with their labels.
Fill the fields
Type the values, tick the boxes, choose from the dropdowns. Fields that are read-only in the form are shown but cannot be changed.
Save, editable or flattened
Choose Keep editable or Flatten, then press Save. The filled copy appears in your library next to the original.
Fill PDF forms is included with a Sealique account; the processing happens in your browser and on our servers, nothing is shared with third parties.
What Fill PDF forms includes
- Text, multiline, checkbox, radio, dropdown and multi-select fields
- Keep editable or flatten
- Read-only fields respected
- Filled copy saved in your library
- Ready to sign
- Works from a phone or a computer
Questions people ask
What does flattening do?
It turns the filled values into page content and removes the form fields, so viewers show the text but nobody can change it.
Flatten before sending a form that must not be altered; keep it editable when someone else still has fields to fill.
My PDF has no fields; what now?
The tool refuses PDFs without form fields; open the file in the PDF editor and add text boxes, check marks or real form fields instead.
Will the values show in every viewer?
Yes. The file asks viewers to regenerate the field appearances, and flattening draws them permanently, so phones, browsers and desktop viewers show the values.
Can I sign the filled form?
Yes. Open the filled copy and add a PAdES digital signature; a flattened form is the safest to sign because its values cannot change.
Does it cost anything?
No. It is included with a Sealique account: no card, no watermark, no daily limit.