AttachKitvs. the big PDF & e-signature tools

The original PDF tool — viewer, editor, signer, form filler, all in one suite.

A cloud "chat with your PDF" assistant — upload documents to ask questions, summarize, and compare, with an AI form-filler, mobile apps, a ChatGPT plugin, and an API.

The popular "chat with your PDF" tool — upload a document and ask it questions, get summaries and cited answers.

A free-leaning browser PDF editor and e-signature tool with deep Google Workspace and Gmail integration.

The market-leading e-signature platform, used by most enterprises.

A mature, lower-cost Adobe Acrobat alternative — desktop editor, cloud, and eSign.

Dropbox-owned e-signature platform, popular with small businesses.

A "ChatGPT for your files" research tool — upload documents to ask cross-file questions and get cited answers, aimed at researchers and teams.

A huge server-side PDF suite — convert, compress, merge, edit, OCR, sign, plus AI tools.

A free, genuinely zero-upload in-browser PDF toolkit — merge, split, compress, convert, all on your device.

A mature, Windows-first Adobe Acrobat alternative (Nitro PDF Pro) plus a cloud e-signature platform (Nitro Sign).

An enterprise-grade PDF SDK that product teams embed into their own apps — now with agentic document editing you build with.

Document automation platform — proposals, contracts, quotes, e-signature.

A popular "chat with any PDF" tool — upload a document and ask it questions, get summaries and cited answers, with a developer API for parsing and extraction.

A free, ad-supported German PDF toolbox — ~30 online tools plus a local Windows app.

A long-running, ad-supported browser PDF editor and form filler.

An online form filler and e-signature service (airSlate) with a huge searchable library of fillable forms.

A free, AI-powered PDF app — local desktop editing plus an AI Copilot and online tools.

A clean, privacy-conscious PDF toolkit — web tools that auto-delete, plus a local desktop app.

Mid-market e-signature from airSlate, popular with SMBs.

Box-owned e-signature with a focus on simplicity and lower pricing than DocuSign.

A clean, affordable e-signature tool for small businesses (formerly Docsketch).

Browser-based PDF tools — convert, compress, edit, sign.

A self-hosted, open-source PDF toolbox — ~50 tools you run yourself via Docker.

A polished, aggressively-marketed cross-platform PDF editor (Windows, Mac, iOS, Android) whose headline feature is "UPDF AI" — chat, summarize, translate, and explain a document.

A mature, full-featured desktop-and-mobile PDF editor (a direct Adobe Acrobat rival) with deep editing, OCR, forms, and an AI assistant.

Apryse's cross-platform PDF suite — strong apps, web tools, Xodo Sign, and AI.