iLovePDF, Smallpdf, or an on-device tool: a fair comparison

We run UnlimitedPDF, so read this with that in mind. We have tried to be accurate about the other two, but their plans and limits change often. Check their pricing pages before you decide. The details below were checked in September 2026.

How they work

iLovePDF and Smallpdf process files on their servers. You upload the file, their servers do the work, and you download the result. Both publish security pages describing encrypted transfer and automatic deletion of processed files after a short period. Both have mobile apps, and iLovePDF also offers desktop apps that can process files offline.

UnlimitedPDF has no server-side processing. Files are read and written by code running in your browser tab. There is no upload step, because there is nowhere to upload to.

What they do better

To be fair about it:

• More tools. Both offer OCR for scanned documents in many languages, e-signatures, PDF editing, conversions to and from Office formats, password protection, and more. UnlimitedPDF has eight tools.
• Heavy files. A server can process a 500-page scanned book that a phone browser will run out of memory on.
• Apps, storage, and teams. Mobile and desktop apps, cloud storage for your documents, and team plans.
• OCR. UnlimitedPDF’s PDF to Word can run OCR in the browser in English only. If you need other languages or high accuracy on difficult scans, a dedicated OCR service will do better.

Where the free plans stop

Both are freemium: free use is limited, and paid plans lift the limits. The exact numbers differ by tool and change over time. iLovePDF’s free plan limits file sizes and how many documents you can process. Smallpdf’s own plan comparison describes its free plan as having limited document downloads, with features such as its strongest compression and direct editing reserved for Pro. For occasional use, many people never hit these limits. For a stack of scans in one afternoon, they come up quickly.

UnlimitedPDF has no plans and no quotas. The practical limit is your device’s memory. A very large scan that fails here fails because the browser ran out of room, and it will usually work on a laptop when it did not on a phone.

Speed is mostly transfer time

With a server-side tool, the file travels twice: up, then down. Our 18.9 MB test scan would take about 16 seconds just to upload on a 10 Mbps connection, before any processing starts. Compressing the same file in the browser here took under two seconds on a desktop, and the result was ready without a download. On a fast connection and a small file the difference disappears. On hotel Wi-Fi or a phone plan, it does not.

Privacy: upload and delete, or never upload

A reputable service with a short retention period is fine for most documents. The difference with in-browser processing is structural rather than a promise: if the file never leaves the device, retention, breaches, and staff access simply do not apply to it. For an ID scan, a medical record, a salary letter, or a client’s contract, that can decide it. Some employers’ policies forbid uploading work documents to third-party converters at all.

UnlimitedPDF shows Google AdSense ads, which is how it stays free. Ads and their cookies are handled by Google; your files are never part of that, because they never reach us or Google. The privacy policy has the details.

When UnlimitedPDF is the wrong choice

• You need OCR in a language other than English, or very accurate OCR.
• You need to sign a PDF, fill in a form, or edit its text.
• You need Word, Excel, or PowerPoint files converted to PDF.
• You have a very large scan and only an older phone.
• You want your documents stored in the cloud between sessions.

Where it fits

• Compressing, merging, and splitting documents you would rather not upload.
• Files larger than a free plan’s size limit, on a laptop or desktop.
• Repeated jobs through the day, with no quota to run out of.
• Checking a PDF for hidden text and metadata before sending it, with PDF X-Ray.

A quick way to choose

If your job is in the bottom half of that table, start with Compress PDF, Merge PDF, or Split PDF. If it is in the top half, the other two are the better tools, and there is no shame in using them for documents that are not sensitive.

What we did not compare

We did not run the same test files through iLovePDF or Smallpdf, and this page does not claim that one tool compresses better than another. Output size depends on the settings each service uses on a given day, and uploading test documents to compare them would only tell you about that day. If output size is what matters most for your file, try it in more than one tool and compare the results yourself, using the checks in the compression guide.

How we measured

The compression timing is from our own test on 27 September 2026 (details in the compression guide). The upload time is arithmetic: 19,803,320 bytes at 10 megabits per second. Descriptions of iLovePDF and Smallpdf are based on their public websites in September 2026.