Sign and Fill PDF Forms

A form job and a signature job are two halves of one sequence, and the order is what makes them work: create the fields, fill the values, check what is really there, sign, then lock the result so every viewer sees the same thing. Nothing here describes the legal effect of a signature — that is set by whoever receives the document, not by a tool. What this hub covers is operational: which tool does which step, in which order, and how to verify each one. It lives in Tool Guides, and the field half of the sequence is How to Create and Fill a PDF Form.

What the family does

• Creating forms places the fields — text boxes, checkboxes, dropdowns, signature placeholders — onto a document, producing real interactive form fields. That is create a fillable PDF form, and changing fields afterward — renaming, marking required, editing option lists, deleting, read-only — is edit PDF form fields.
• Filling forms types the values into fields someone else placed: fill a PDF form, which auto-detects the fields and exports flattened by default.
• Checking forms shows the form the way a machine sees it: inspect PDF form fields lists every field’s name, type, value, and read-only state.
• Moving values gets data in and out without typing: PDF form data import/export exports JSON, FDF, or CSV and refills from JSON.
• Locking values bakes the fields into the page so they display in any viewer: flatten a PDF. It is irreversible, so the unflattened original is kept.
• Signing runs after the values are in place: sign a PDF places the signature in your browser, and sign a PDF with a digital certificate runs PAdES signing on PDFLean’s encrypted cloud path and uses plan quota.

Every step except the PAdES certificate signing runs in your browser with no account and no upload.

The guides in this family

Guide	What it covers
How to Create and Fill a PDF Form	The field-side sequence: create, fill, check, move values, lock — the tool for each step
Sign a Contract and Return It	The signature-side sequence: read, fill, sign, return — and what each step protects
Collect Signed Consents	The distribution version: one form, many signers, values collected back into a spreadsheet

A ready-made consent acknowledgement template is downloadable for the collect-from-many-people job — the fields are already placed.

The tools

Tool	What it does	Where it runs
create a fillable PDF form	Design forms with text fields, checkboxes, dropdowns, signature placeholders	Browser, free, no upload
edit PDF form fields	Rename, required flags, options, delete, read-only, flatten, XFA inspection	Browser, free, no upload
inspect PDF form fields	List every field: name, type, value, read-only state	Browser, free, no upload
fill a PDF form	Type values into a finished form; flattened export by default	Browser, free, no upload
PDF form data import/export	Export values as JSON/FDF/CSV; refill from JSON	Browser, free, no upload
flatten a PDF	Bake fields into read-only page content; irreversible	Browser, free, no upload
sign a PDF	Place a signature on the page	Browser, free, no upload
sign a PDF with a digital certificate	PAdES signing with certificate, reason, and location	Encrypted cloud path — account and quota apply
verify a PDF signature	Check what a signature says: certificate, signer, and whether the document changed after signing	Encrypted cloud path
overlay a letterhead on a PDF	Overlay or underlay letterheads and stationery onto pages	Browser, free, no upload
watermark a PDF	Text or image watermark, tiled or nine-position grid	Browser, free, no upload
annotate a PDF	Add annotations and comments	Browser, free, no upload
highlight text in a PDF	Highlight text before review	Browser, free, no upload

What order do the steps run in?

Create or fix the fields first, fill the values, verify what is there, sign, then flatten for distribution. The most common failure in this family is a step run out of order: a signature applied before the values are final, or a form flattened while someone still needs to fill it. Each guide above lists its own sequence with the checks between steps.

Frequently Asked Questions

Is filling and signing free? Everything except the PAdES certificate signing runs in your browser, free, with no account and no upload. The certificate signing tool and the signature verification tool run on the cloud path; which tools use quota is on Free vs Paid on PDFLean.

Which signature tool should I use? That is set by whoever receives the document. The operational difference: sign a PDF places a signature on the page in your browser; sign a PDF with a digital certificate runs PAdES signing on the encrypted cloud path, and each tool page describes exactly what it does.

Why does my filled form arrive with empty boxes? Some viewers ignore form fields, so the values are inside the file but not displayed. Flatten a PDF bakes the values into the pages so any viewer shows them — this is why filling exports flattened by default.

Can I fill a form that has no fields? Yes, but the fields have to be placed first. If the visible lines and boxes are just drawn artwork rather than interactive fields, place real fields with create a fillable PDF form on top of the drawing. The inspection tool tells you which case you have.

What happens to my file on the cloud path? Cloud tools transfer the file over an encrypted connection and the output is kept for the site’s one retention window and then automatically deleted — the retention rule applies to every cloud output. The browser tools never upload anything at all, so there is nothing to keep.

Can a form be filled on a phone? Yes — these tools run in the browser, so any device with a modern browser works. Browser support details are on the browser compatibility reference page.

Related reading

• How to Create and Fill a PDF Form — the field-side sequence in full
• Sign a Contract and Return It — the signature-side sequence in full
• How Long Are My Files Kept? — the one retention rule behind the cloud tools on this hub