Free PDF Filler Online — Fill Any Flat or Interactive PDF Free

Start by navigating to the JustFill editor and clicking "Upload PDF" or dragging your file directly onto the page. JustFill accepts PDF files up to 50 MB on the free and paid tiers.

If you're working with a scanned document:

• Scan at 300 DPI or higher for the sharpest rendering. AI field detection is noticeably more accurate at 300 DPI compared to the typical 150 DPI default on most scanners.
• Use a flatbed scanner over a phone camera when possible. Phone scans often have perspective distortion and uneven lighting that makes text harder to read.
• Save as PDF, not JPEG. If your scanner gives you image files, combine them into a single PDF using your OS's built-in print-to-PDF feature before uploading.

If your PDF came from Word, Excel, or Google Docs:

• These are "flat" PDFs — they look like forms but have no interactive fields. JustFill handles them perfectly. Just upload the file as-is.
• Avoid password-protected PDFs. If the file requires a password to open, remove the protection first using your PDF viewer's security settings.

Manual field drawing (free):

• Click the "Add Field" button, then click and drag on the PDF to create a text field exactly where you need it. Position it over the blank line, checkbox, or area you want to fill.
• Resize fields by dragging the corner handles. Make the field large enough to fit your text comfortably — the font size adjusts automatically to fit the field dimensions.
• Multi-page forms: scroll down to navigate between pages. Fields are page-specific, so you can work through a 20-page document one page at a time without fields from page 1 interfering with page 5.

AI auto-detection (fair-use free):

• Click "Detect Fields" and the AI analyzes the entire document, identifying every fillable area — text lines, checkboxes, date fields, signature blocks, and more.
• Review the detected fields and adjust any that need repositioning. The AI is accurate on well-structured forms but may need minor tweaks on unusual layouts.

Entering data:

• Click on any field and start typing. Use Tab to move between fields quickly — this is especially useful on long forms with dozens of fields.
• Voice dictation (paid): click the microphone icon and speak your data. Supports English, Polish, German, French, and Spanish. Useful when you're filling the same information across multiple forms and don't want to retype it.

When you're done filling, click "Download" in the top toolbar. Your filled PDF downloads immediately from your account — no waiting queue. Watermarked preview downloads are free (hand-filled PDFs up to 1 page); a $7 7-Day Pass unlocks 25 clean flat PDF pages ($7 credited toward Starter).

• Clean, professional output. Your clean downloads are identical to the original PDF with your data rendered directly onto the pages. Recipients can't tell it was filled with JustFill.
• Original quality preserved. The PDF resolution, fonts, colors, and layout remain exactly as they were. Your filled data appears as native PDF text, not as an image overlay.
• Save as template: if you'll need to fill this same form type again (monthly reports, recurring invoices, quarterly filings), click "Save Template" to store the field layout. Next time, upload a blank form and load the template — all your fields appear instantly, ready for new data.

Pro tip: before downloading, scroll through every page to double-check your entries. It's easy to miss a field on page 3 of a long form. The field list panel on the left shows all fields across all pages — any empty fields are highlighted so you can spot gaps quickly.