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Filly AI vs pdfFiller

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. Filly AI starts at $19, pdfFiller at $8. Only Filly AI has a free tier. Only pdfFiller ships a public API.

Filly AIReads a PDF or Word form with AI and auto-fills it from saved client profiles.pdfFillerBrowser-based PDF editor and e-signature tool from airSlate, with a REST API and native iOS, Android, and Mac apps.

Side by side

FactFilly AIpdfFiller
CategoryForm Filling & AutofillE-signature & Document Workflow
Pricing modelFreemiumPaid
Starts at$19 month$8 seat_month
Public APINoYes
PlatformsWebWeb, iOS, Android, macOS, API
CompanyCyrus Group Kft.airSlate Inc.
Last verifiedSep 1, 2026Sep 1, 2026

What our research says

Filly AI

Filly AI is built around a genuinely repetitive task, refilling the same form for different clients, and the batch mode plus e-signature step cover that workflow end to end. It's narrow by design, though: this is a forms tool, not a general document editor or contract analyzer.

Pros

  • Batch-fills the same form for multiple clients at once
  • Includes e-signature and basic PDF merge/split in the same tool
  • Free tier requires no card to try 10 forms
  • Operator and country are clearly disclosed (Cyrus Group Kft., Hungary)

Cons

  • Free plan's 10 fills a month is thin for daily professional use
  • Scope is limited to forms; it is not a general PDF editor or e-signature platform on its own

pdfFiller

pdfFiller covers the ordinary PDF-editing-plus-signature workflow well: fill fields, merge and convert files, collect signatures, and sync across a web editor and native mobile/desktop apps. It's an established airSlate product with a real API for teams that want to automate document handling rather than click through a UI. The catch is that the official pricing page didn't surface exact figures during this check, so the entry price here comes from third-party trackers rather than the vendor directly.

Pros

  • Native apps for iOS, Android, and Mac in addition to the web editor, so documents follow you across devices
  • Documented REST API with OAuth 2.0 authentication for filling, signing, and converting documents programmatically
  • 30-day free trial before any card is charged

Cons

  • Official pricing did not surface on the site during this check — the confirmed number comes from third-party trackers, not the vendor page
  • Monthly, non-annual billing carries a documented markup over the annual rate

Which one fits

Choose Filly AI if you need

  • Immigration lawyers and paralegals filing the same forms repeatedly
  • HR and insurance staff processing many client forms per week

Choose pdfFiller if you need

  • Teams that need PDF editing and e-signature in one subscription across devices
  • Developers automating document fill/sign workflows via API

Browse all Form Filling & Autofill →