PDF Forms Online
Fill out existing PDF forms or create custom fillable text fields, checkboxes, dropdowns, and signature areas online for free.
PDF Forms
Fill, create, and edit PDF form fields online with zero software install.
What are PDF Forms?
The modern standard for paperless agreements, applications, and official documentation.
An interactive PDF Form (also known as an AcroForm) is an electronic document formatted with digital input widgets that allow individuals to submit structured information without printing, writing by hand, or scanning.
Unlike static PDF pages that treat text as unchangeable graphic objects, fillable PDF forms maintain dedicated metadata for field names, defaults, validation rules, and input constraints. Common form widgets include single-line text boxes, multi-line paragraph areas, checkboxes, mutually exclusive radio groups, dropdown selectors, and electronic signatures.
How to Fill a PDF Form in 3 Simple Steps
Upload Form
Drag and drop your fillable PDF into the studio above. BigPDFHub automatically detects all existing AcroForm fields.
Complete Fields
Click directly into text boxes, check terms, select dropdown options, and draw your legally binding e-signature.
Export & Download
Click Download PDF. Your entered information is preserved in standard AcroForm format or permanently flattened.
How to Create a Fillable PDF & Add Fields
Transform any flattened contract, invoice, or questionnaire into an interactive form.
1. Switch to Edit Form Mode
Use the top mode toggle to enter Edit Form mode. The form-field toolbar will activate, giving you access to all widget creators.
2. Pick & Position Field Types
Select from Text Field, Checkbox, Radio Button, Dropdown, List, Date, or Signature. Click anywhere on the document canvas to position the widget.
3. Customize Properties
Use the right-side properties panel to assign field keys, placeholder labels, required validation, font sizes, text alignments, and menu items.
4. Save as Standard Fillable PDF
When you export, BigPDFHub generates authentic PDF form widgets readable across all standard PDF readers, desktop viewers, web browsers, and mobile devices.
Frequently Asked Questions
What are PDF forms?
PDF forms are electronic documents that contain interactive fields (such as text inputs, checkboxes, radio buttons, dropdown menus, and signature boxes) that users can fill out directly on computers, tablets, or smartphones without printing.
How do I fill a PDF form on BigPDFHub?
Simply upload your PDF. If it has existing fillable AcroForm fields, BigPDFHub opens Fill Form mode immediately. Click on any text box to type, check boxes, pick dropdown items, or draw your digital signature, then click "Download PDF".
Can I add fillable fields to a flat or scanned PDF?
Yes! If your PDF is flat or scanned, BigPDFHub offers two options: click "Detect automatically" to scan labels and underline blanks, or choose "Edit/add manually" to draw custom text fields, checkboxes, and signatures anywhere on the page.
What is the difference between Fill Form and Edit Form mode?
Fill Form mode allows you to interactively type data, check boxes, and sign without accidentally moving fields. Edit Form mode allows you to create new fields, move or resize existing boxes, set default values, and configure required validation rules.
Are my uploaded PDF forms safe and confidential?
Yes, 100%. All communications are secured using end-to-end 256-bit TLS encryption. Files are processed in memory and permanently deleted from our servers automatically within 60 minutes.
What is the "Flatten form" option?
When you check "Flatten form" before downloading, all filled values and added fields are permanently baked into standard PDF page drawings. This locks the fields so future readers cannot change your entered answers.
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