Intelligence
PDF Form Filler Online – Fill, List and Flatten Fillable PDF Forms
List, fill or flatten the fillable fields in a form.
Runs on your deviceWorks with: A PDF with fillable form fields. A flat document has none — use the editor instead.
Your files never leave this device — everything above runs locally.
A PDF form filler that shows you the field names
Jobsixo works as a PDF form filler for documents with real fillable fields: application forms, declarations, registration sheets, tax and bank forms. It does three things. It lists every field the form contains, it fills fields from values you type, and it flattens the result so the answers become part of the page and can no longer be edited.
The listing step is what makes the rest dependable. Instead of guessing what a field is called, you read its exact name and then fill it by that name. Everything runs in your browser, so a form full of personal details is never uploaded.
How to fill a PDF form online
- Drop the form on the upload area, or click it to browse. This tool takes one PDF at a time.
- Leave What to do on List the fields and press Run. The fields appear on the page, one per line, with a name, a short type tag and the current value, and a form-fields.txt download holds the same text.
- Switch What to do to Fill the fields. A box labelled Values, one per line as name=value appears.
- Type a pair in that box, for example fullName=Anita Rao, using the name exactly as the listing showed it. The box is a single line, so each run fills one field.
- Press Run and read the note: it says how many of the fields you named were filled. Download filled.pdf.
- For the next field, add filled.pdf as the input and repeat. When every answer is in, choose Fill, then flatten and press Run to lock the form. The download is flattened.pdf.
How the tool reads and fills a form
Interactive PDF forms store their fields in a structure called an AcroForm. The tool opens that structure with pdf-lib, a JavaScript library that runs in the page, and walks through every field. Each one has a type, and the type decides what a value means.
A text field takes whatever you type. A checkbox is ticked if the value is yes, true, 1 or on, in any capitalisation, and cleared for anything else. A radio group or a list box needs one of its own option labels, spelled exactly as the form defines them, and a label that does not exist is skipped silently. So is a field name that does not exist, which means a typo costs you the field rather than crashing the run. A dropdown is more forgiving than it should be: it can accept a value that is not on its list, so check the result.
What the three actions do
| Action | What you get | Can the form still be edited? |
|---|---|---|
| List the fields | A text listing of names, types and current values, plus form-fields.txt | Not applicable, no PDF is produced |
| Fill the fields | filled.pdf with your values placed in the matching fields | Yes, every field is still live |
| Fill, then flatten | flattened.pdf with the values drawn onto the page | No, the fields are gone |
Flattening is the step that turns a form into a document. The values stay visible and print exactly as they appear, but there is nothing left to click into. It is the usual last move before sending a completed form to someone who should not alter it.
A worked example
Take a two-page admission form with five fields: fullName and dob as text boxes, city as a dropdown offering Delhi, Mumbai and Pune, agree as a checkbox and plan as a radio group with Basic and Pro. Run List the fields first and you see all five names and their empty values.
Run one fills fullName=Anita Rao, and the note reads 1 of 1 field(s) filled. Run two uses the downloaded filled.pdf and sets agree=yes. Run three sets city=Delhi. The fourth run uses Fill, then flatten with plan=Pro, and the note reads 1 field(s) filled, then flattened so they are no longer editable. That is four runs for four fields, and a fifth would be needed for dob. If you list the fields of flattened.pdf, the tool reports that it has no fillable form fields, which is the quickest way to confirm the lock worked.
How to read the notes and the listing
After a fill run the note has the shape X of Y fields filled. Y counts the lines you typed that contain an equals sign, and X counts those that were applied. If X is lower than Y, a name or an option label did not match, so go back to the listing and copy the name character for character. Names on official forms are often long, with brackets and numbers, and they are case-sensitive.
A flatten run reports only how many fields it filled. Treat the count as a hint rather than proof and open the result: a name that matches a button or signature field is counted although nothing visible changes. If the form-fields.txt listing shows a value as empty, nothing has been entered in that field yet.
The kinds of field you will meet
- Text fields: names, dates, addresses and numbers. These take any text you give them, within the limits of the font.
- Checkboxes: on or off, set with yes, true, 1 or on.
- Radio groups: a set of options of which exactly one can be chosen, set by the option's label.
- Dropdowns and list boxes: pick from a fixed set of choices.
- Buttons: usually Submit or Print controls. They appear in the listing but have no value to fill.
- Signature fields: placeholders for a digital signature, which this tool leaves untouched.
Why a form may show no fields
A PDF that looks like a form is often just a picture of one, or a typeset page with boxes drawn on it. Those have no fields, and the tool says so instead of pretending. Scanned forms are the same: pixels, not controls. In that case you type on top of the page, which is what an editor does.
A second cause is the form's construction. Fields built in the older XFA format are not part of the standard form structure that this tool reads, so a form that works in one desktop reader can appear empty here. If a listing is blank for a form you know is interactive, that is the likeliest explanation.
When to use it
- Completing a government or university application that arrives as a fillable PDF.
- Checking which fields a form has before you build or share it.
- Locking a signed-off form so the figures cannot be changed in transit.
- Preparing the same form for several people by filling the fixed fields once.
- Making a completed form print and display identically in every viewer, including ones that ignore interactive fields.
Tips for smoother form filling
- Always list first, and copy field names from the listing rather than retyping them.
- Keep the empty form and every intermediate file until you are satisfied. Flattening cannot be undone.
- Flatten last. A flattened file has no fields left, so nothing more can be filled into it.
- Check dropdowns and radio groups against the form itself. Radio labels must match exactly, and a dropdown can accept a value it does not offer.
- If you need a signature, stamp a signature image after flattening.
Long field names on official forms
Forms produced by large organisations rarely use friendly names such as fullName. A typical field is called something like topmostSubform[0].Page1[0].f1_01[0], and the listing shows it in full. Do not try to shorten or tidy it. The name is looked up exactly, so select it in the listing, copy it, and paste it before the equals sign.
If several fields look alike, fill one, download the result and list the fields again. The new listing shows the value now sitting in each field, which makes it obvious which name belongs to which box on the page.
Using the form step inside a workflow
The workflow builder includes a Fill form fields step with two actions, Fill the fields and Fill, then flatten, because only those hand back a PDF that the next step can use. It has the same values box, so the single-line behaviour applies there as well. It is most useful for a form whose fixed answers never change, such as an organisation name, followed by compressing or protecting the result.
Mistakes and how to avoid them
- Typing the label printed on the page instead of the internal field name. They are often different.
- Putting several pairs in the box and expecting them all to apply. Only one pair fits in the single-line box.
- Flattening first, then discovering a typo. Run Fill, check the result, and flatten at the end.
- Expecting a scanned or flat document to have fields. Those have to be typed onto with Edit PDF instead.
- Using Hindi or other non-Latin text. See the limits below.
Limits and honest limitations
Text is written with a standard Latin font, so accented letters such as the e in José work, but scripts like Devanagari do not. The run stops with a message that the character cannot be encoded. For those names, flatten the form and place the text with the editor instead.
Only AcroForm fields are supported. Some forms are built with XFA, an older Adobe format, and may show no usable fields here. A form with a digital signature field can be listed, but the field is not signed by this tool. Files must be under 100 MB and 500 pages, and an encrypted form is refused, with a pointer to the unlock tools. A PDF with no fields at all returns the message that it has no fillable form fields.
Your form stays on your device
Reading, filling and flattening all happen inside your browser tab. The form and the answers you type are not sent to a Jobsixo server, and no account is needed. The downloaded file is created on your machine.
Related tools
If a form refuses to open because of a password, unlock the PDF first. After filling, you can shrink the file for an upload portal, or protect the form with a password before it is emailed. Forms you complete repeatedly can sit in a saved workflow, which includes a Fill form fields step.
Frequently asked questions
How do I fill a PDF form online for free?
Add the form, list its fields, then choose Fill the fields and enter name=value for each answer. Download filled.pdf. There is no account and no watermark.
What does it mean to flatten a PDF form?
Flattening converts the filled fields into fixed page content. The answers still show and print, but nobody can click into a field and change them.
Why does the tool say my PDF has no fillable form fields?
The document is flat, meaning the boxes are only drawn on the page. It could also be a form type that this tool cannot read. Use the editor to type onto a flat page.
How do I find a field's name?
Run List the fields. Each line starts with the field's exact name, which is what you must type before the equals sign when filling.
How do I tick a checkbox?
Use the field's name and one of yes, true, 1 or on, for instance agree=yes. Any other value clears the box.
Can I fill several fields in one run?
The values box is a single line, so one name=value pair is practical per run. To fill more fields, download the result and use it as the input for the next run.
Can I undo flattening?
No. Once flattened, the fields are gone from the file. Keep an unflattened copy if you might need to change an answer.
Is my form uploaded to a server?
No. The form is processed in your browser, so the details you enter never leave your device.
Can I fill a form in Hindi?
Not with this tool. It writes text in a standard Latin font, and Hindi characters cause the run to stop with an encoding message. Latin letters with accents work.