Smallpdf is polished and widely trusted. It is also cloud-first: every free task is an upload. If that is the part you want to avoid, read on.
| What matters | Smallpdf | AIMerger |
|---|---|---|
| Where your file is processed | Uploaded to their servers | Inside your browser — never uploaded |
| What happens to the file afterwards | Deleted from their servers after a set period, per their policy | Nothing to delete — it never left your device |
| Free tier | Free tier with a daily task limit; Pro subscription removes it | Unlimited for every file, video, audio and data tool |
| Account required | Optional; needed for Pro | Never |
| Ads | On the free tier | None |
| Works offline | No | Yes — install it as an app |
| AI photo merging | No | Yes — people, pets, products, styles |
| PDF editing, signing, compression, OCR | Yes — editing, e-signing, conversion, compression | Compression to a target size, OCR and page numbers: yes, in your browser. Text editing and e-signing: not offered |
Checked September 2026. Competitor plans and limits change; confirm them on Smallpdf's own pricing page before deciding. The one row that does not change is the first: they process files on their servers, AIMerger processes them on yours.
Smallpdf is a full PDF suite. If you need to edit text inside a PDF, convert Word to PDF or e-sign, Smallpdf does those and AIMerger does not. (AIMerger does now compress to a target size, read scans with OCR and add page numbers — all in your browser.) AIMerger is deliberately narrow: it merges things, and it does that without ever seeing your file.
Anyone who hits the free daily limit and does not want a subscription just to merge two files, and anyone handling documents that should not be uploaded anywhere. AIMerger has no daily counter on file tools because your own device does the work.
100% in your browser — contracts, statements and IDs are never uploaded anywhere.
📄 Drop 2–50 PDF files here, or click to choose
Reorder them below with ▲ ▼ (or drag), then merge into a single PDF
🔏 A digitally signed PDF is included: its signature will not be valid in the merged file (the visible signature stays).
🔒 Up to 50 PDFs per merge; the practical size limit is your device’s memory (about 500 MB in total on a computer, less on phones). Password-protected PDFs need the password removed first.
Drop your PDFs onto the box or tap to choose them.
Use the ▲▼ arrows to reorder; ✕ removes anything you don't need.
Press 🔀 Merge PDFs. Everything runs inside your browser — nothing is uploaded.
Press ⬇️ Download merged PDF — no watermark, no daily limit, no signup.
💡 Tip: Need images in a PDF too? Use the free Images to PDF tool first, then merge.
For every file, video, audio and data tool, yes — unlimited, no watermark, no account. AI photo blending has free daily tries and optional credit packs.
A file that is never transmitted cannot be intercepted, retained, breached or subpoenaed from a third party. For contracts, statements, medical and ID documents that is the whole question.
For merging — and now compressing to a target size, OCR and page numbers — yes. Smallpdf also offers text editing, file conversion and e-signing, which AIMerger does not — see the table.
Client-side tools cost almost nothing to run because your device does the work. AIMerger earns from optional AI credit packs instead.
Everything on AIMerger brings things together — here is what pairs with this one.