Free online PDF tools compared: limits, accounts and where your file goes

Most online PDF services look the same on the surface: a row of tiles, drop a file, download the result. The differences show up when you hit a limit. One service stops you after two tasks a day, another after three an hour, another when the file passes 15 MB. Some keep the file on their server for a while, some never see it at all. This page puts those facts next to each other.

Everything here was read from each service's own pricing, help or tool pages on the date at the top of this page. Prices and limits change; if a figure matters for a decision, check it on the service's own site that day. Nothing below is a rating, and no service is named the winner, because the right choice depends on what you need to do.

What to compare

• How much is free. A daily or hourly task count, or a file-size cap, decides whether a service is usable for a day's work without paying.
• The largest file. Scans and photo-heavy PDFs are often 50 to 200 MB. A 15 MB cap rules them out.
• An account. Some services work without one; some ask you to sign in after the first task.
• Where the file is processed. In your browser, or on the service's server. If it is the server, how long the copy stays.
• Scanned pages. OCR turns a scanned page into text you can search and copy. It is the feature most often held back for paid plans.
• Signed PDFs. Signing is everywhere. Checking whether an existing signature is valid, and whether the document changed after it was signed, is rare.

The table

A few details that do not fit in a table cell:

• iLovePDF: Merge takes up to 25 files, Compress 2 files and most conversions 1 file. Compress accepts up to 200 MB and the Office conversions 15 MB. OCR inside the Word and Excel conversions, PDF to PDF/A and the apps are paid. Premium is US$4 a month billed yearly, or US$7 month to month.
• Sejda: Compress accepts up to 100 MB and JPG to PDF 5 MB. Web is US$7.50 a month, Desktop and Web US$63 a year, and a one-week pass costs US$5.
• PDF24: says it is "free of charge and without restriction", companies included, and offers a free desktop program as well. Its signature checker is called "Verify PDF signatures".
• Smallpdf: its help pages describe two free tasks a day, then a 24-hour wait or an upgrade. Whether OCR counts against that limit is not stated.
• KovaPDF: the hourly cap exists so that one person cannot slow the service for everyone. OCR reads the first 30 scanned pages of a document in one run.

"No such tool listed" means the service's own tool list, read on the review date, has no tool for checking an existing signature. It may have one inside another feature.

Where files are processed

This is the part most pages skip, and it is the part that matters if the PDF is a contract, a medical record or someone else's data.

• KovaPDF runs about half its tools inside your browser, so the file is never uploaded: merging, splitting, rotating, cropping, page numbers, password protection and removal, text extraction, image conversions and more. The rest use the server and delete the working copy as soon as the result is built. Each tool page says which it is, and the full list is in which PDF tools never upload your file.
• PDF24 processes online tools on its server and says files are deleted within one hour, or sooner if you remove them yourself. Its desktop program works offline, so nothing leaves the computer when you use that instead.
• iLovePDF, Sejda and Smallpdf process files on their servers. Each publishes its own deletion period on its privacy or security page; those pages were not checked for this comparison, so no figure is given here.

Where KovaPDF is weaker

Being honest about this is the point of the page.

• There is no desktop program and no phone app. Sejda, iLovePDF and Smallpdf offer desktop or mobile apps on their paid plans, and PDF24's desktop program is free.
• There is no batch of several files in one go for most tools, and no saved workflows of the kind Sejda offers.
• The tool count is smaller than PDF24's, which has specialist tools such as e-invoice creation and bookmark editing.
• Summarize PDF has a daily allowance, the same for everyone, and its page says so.
• Conversions to and from Word, Excel and PowerPoint, OCR, compression and the editor need the server, like the other services. Only the page and image tools stay in the browser.

Where KovaPDF is stronger

• No account for any tool except Request Signatures, and no daily task count.
• The browser-only tools: for those jobs the file does not leave your device at all.
• Verify Signature checks an existing digital signature and gives you a report. Among the five services here, only PDF24 lists a comparable tool.
• Pages and tools in 26 languages, with the same limits in every language.
• Two tools nobody else on this list has: Bijoy to Unicode and Unicode to Bijoy for Bangla text.

Checking a signed PDF

If someone sends you a signed contract and you need to know whether the signature is real and whether the file was changed after signing, you need a checker, not a signing tool. KovaPDF's Verify Signature reads every signature in the file and reports, for each one: whether the signature itself is intact, whether the document was changed after it was applied, who signed and when, whether the certificate was valid at the time, whether the certificate chain is complete, whether the issuer is on a recognised trust list, whether a trusted timestamp is present, and the PAdES level. You can download the result as a PDF report or as a standard validation report. The post how to read a signature check result explains each line.

PDF24 lists a tool with the same purpose. The other three services on this page offer signing but no checking tool in their lists.

Picking by situation

• A few files a week, nothing large: any of the five.
• A long day of work on many files, no budget: PDF24 or KovaPDF, since neither counts tasks. Sejda's three an hour and Smallpdf's two a day run out quickly.
• Files over 80 MB: iLovePDF (100 to 200 MB free, depending on the tool) or PDF24. KovaPDF stops at 80 MB.
• Scanned documents you need to search: KovaPDF (30 pages a run), PDF24, or a paid plan on Sejda or iLovePDF for long scans.
• A file you would rather not upload anywhere: a KovaPDF browser-only tool, or PDF24's offline desktop program.
• Checking a signed contract: KovaPDF or PDF24.
• A desktop or phone app: PDF24 (free desktop), or a paid plan on Sejda, iLovePDF or Smallpdf.