Dev tools · alternatives · 2026

24 alternatives to PDF Otter

Meet the PDF Otter API. Automate filling in PDFs

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. PDF Otter launched in 2017; newer entries below may have overtaken it.

1. 1PO
   PDF Otter – Fill in PDFs Online and API▲109

   Fill in PDF templates with the PDF Otter API. Use it to accept eSignatures in your app, repeatedly fill in common PDF forms, or build large scale apps around PDF documents.

   2017 · pdfotter.com · its alternatives →

2. 2
   Anvil PDF API▲185

   Twilio for PDFs: esign, fill, generate PDFs with one API

   2021 · useanvil.com · its alternatives →

3. 3
   PDF.ai▲677

   Chat with any document

   2023 · pdf.ai · its alternatives →

4. 4
   An API for filling out PDF forms▲209

   Fill out and generate PDFs with a simple API request. Design templates in our drag-and-drop editor, POST your JSON data, and download a finished PDF in seconds.

   2017 · formapi.io · its alternatives →

5. 5
   Anvil PDF Filling API▲205

   The easiest way to programmatically populate any PDF

   2020 · useanvil.com · its alternatives →

6. 6
   FormAPI▲230

   Stripe for PDFs

   2017 · docspring.com · its alternatives →

7. 7
   Pdf-Bot, an API/CLI for Generating PDFs Using Headless Chrome▲235

   🤖 A Node queue API for generating PDFs using headless Chrome. Comes with a CLI, S3 storage and webhooks for notifying subscribers about generated PDFs - esbenp/pdf-bot

   2017 · github.com · its alternatives →

8. 8
   PDF Expert for Mac▲187

   The best PDF viewer, editor, and form filler available.

   2015 · apps.apple.com · its alternatives →

9. 9
   Document Automation Hub by airSlate▲223

   Every API you need to automate document workflows

   2024 · developers.altaflow.com · its alternatives →

10. 10
    PDFMonkey▲164

    Automate your PDF generation, get the job done

    2023 · its alternatives →

11. 11
    PDF.ai Free tools▲230

    Free PDF tools, merge, split, compress, compress, rotate etc

    2023 · pdf.ai · its alternatives →

12. 12
    PDF Viewer▲161

    Read, review, and annotate PDFs with ease

    2016 · pdfviewer.io · its alternatives →

13. 13
    PDFToolkit for Mac▲85

    PDF merger, splitter, compressor and image + text extractor

    2015 · cisdem.com · its alternatives →

14. 14
    PDF Vector▲57

    AI-Powered Document Processing for Developers & No-Coders

    2025 · pdfvector.com · its alternatives →

15. 15
    Elephant Folio▲69

    The PDF Library that automatically organizes itself

    Apr 2026 · beroea.tech · its alternatives →

16. 16
    Rapid Doc▲68

    All in one PDF tools and scanner app

    2020 · play.google.com · its alternatives →

17. 17
    LINER AI for PDF▲95

    The greatest AI tool where PDF becomes personal assistant

    2023 · dynamic-link.getliner.com · its alternatives →

18. 18
    PDF merge API▲98

    Create PDF documents from data and templates

    2024 · its alternatives →

19. 19AA
    an API to extract text from a PDF▲51

    2013 · stamplin.com · its alternatives →

20. 20
    e-Doc▲74

    Scan and convert your pdf file into an audio book

    2022 · apps.apple.com · its alternatives →

21. 21PI
    PDFFiddler – Intelligent Automation for PDF Processing▲13

    2020 · playground.pdffiddler.com · its alternatives →

22. 22
    OtterSearch▲6

    AI search for PDFs & images. Better than Spotlight.

    Jan 2026 · github.com · its alternatives →

23. 23
    PDF Sign & Fill▲7

    Best app for signing, editing pdf documents

    2025 · apps.apple.com · its alternatives →

24. 24
    PDF Explorer▲7

    Your AI-Powered PDF Assistant

    Nov 2025 · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →