"Which PDF tool is best" is the wrong question, because these three barely compete for the same job. Adobe Acrobat edits existing PDFs. SmallPDF converts and compresses files you already have, one at a time, in a browser tab. PDFly generates documents from data, either through an API or a browser tool that runs entirely client-side. Picking wrong usually means you asked the wrong tool to do a job it was never built for.
## PDFly
Built around generation, not editing. A REST API for turning data into PDFs programmatically, plus a browser tool that does the same thing for a human sitting at a keyboard, with every conversion happening client-side, nothing uploaded.
- **Pricing:** free, no card required. There is no paid tier yet, which we would rather say plainly than dress up as a limited-time offer. - **API:** full REST access, 100 documents a month, 60 requests a minute, 5 documents per batch call. - **Privacy:** the browser tools never upload a file. Everything happens in the tab. - **Scripts:** Latin, Devanagari and Arabic script render correctly, on both the browser tool and the API, with the matching font embedded automatically. Chinese, Japanese, Korean, Hebrew and Thai are not supported on either surface, and we say so rather than let you find out mid-project. - **Image to PDF:** 25+ formats including HEIC and RAW camera files, 100+ images per document. - **Templates:** 15 built-in, no watermark on any of them. - **Best for:** generating documents from your own data, privately, without standing up rendering infrastructure.
## Adobe Acrobat
The original, and still the deepest editor: form creation, digital signatures, redaction, advanced markup, the tool a legal or compliance team reaches for when a document needs real editing rather than generation.
- **Pricing:** free reader; Acrobat Pro from roughly $20/month. - **API:** Adobe PDF Services API exists, paid, with real setup overhead. - **Best for:** editing PDFs that already exist, signatures, forms, redaction, anything beyond generation.
If the job is editing a contract someone else already produced, this is very likely the right tool and nothing on this page changes that.
## SmallPDF
A browser-based toolkit built for one-off conversions and compression, aimed at someone who needs to shrink or convert a single file right now without installing anything.
- **Pricing:** free tier capped at 2 tasks a day; Pro from around $12/month. - **API:** none public. - **Best for:** an occasional single conversion or compression, not a workflow you'd want to automate.
The files you process through SmallPDF's web tools do get uploaded to their servers, which is the tradeoff for not needing an account for basic use.
## Where the actual decision sits
If you need to edit, sign or redact a PDF that already exists, that's Adobe's job, not ours or SmallPDF's. If you need a single quick conversion right now and don't want to touch an API, SmallPDF's browser tool is built for exactly that. If you're generating documents, invoices, certificates, reports, from your own data, and would rather that never leave your device or your own server, that's what we built PDFly for: an API with a real free tier and no card required, plus a browser tool where the processing never leaves the tab, in Hindi, Arabic or English without any extra setup on your part.