Free PDF tools compared: browser-based, server-based and desktop
Free PDF tools fall into three groups: browser-based tools that process files on your device (such as OnCloudPDF), server-based online tools that upload your file (such as Smallpdf, iLovePDF and the PDF24 online tools), and desktop software (such as PDF24 Creator, Adobe Acrobat or the Preview app on macOS). Browser-based tools suit quick, private edits; server-based and desktop tools are usually stronger for heavy conversions, high-accuracy OCR and image compression.
Updated · Runs in your browser, no upload, no account
The comparison at a glance
The table compares the three approaches, not individual brands, because plans and limits change often. Where a point depends on the provider it says so; check each provider's current terms and pricing page before relying on it.
| Criteria | Browser-based (e.g. OnCloudPDF) | Server-based online tools (e.g. Smallpdf, iLovePDF, PDF24 online) | Desktop software (e.g. PDF24 Creator, Acrobat, Preview) |
|---|---|---|---|
| Where your file is processed | In your browser, on your device | On the provider's servers after you upload it | On your computer |
| Install needed | No | No | Yes |
| Account needed | No (OnCloudPDF) | Varies by provider and by plan | Varies by product |
| Works with sensitive documents | Good fit: the file is not uploaded | Read the provider's retention policy first | Good fit: stays on your computer |
| Heavy conversions (layout-faithful PDF to Word, strong OCR) | Limited: text extraction and Tesseract OCR in 8 languages | Often stronger | Often stronger |
| Image compression to hit a target size | Not supported (Compress only optimizes structure) | Commonly offered, varies by provider | Commonly offered, varies by product |
| Free-tier limits | No size or usage limit enforced; device memory is the limit | Often task, size or speed limits (varies by provider) | Varies; some editing features require a paid licence |
| Works offline | No, the page must load first | No | Yes |
Where OnCloudPDF is a good fit
- Merging, splitting, reordering, rotating, extracting or deleting pages when you do not want to upload the file.
- Quick one-off jobs on a computer or phone where you do not want to install software or sign up.
- Small utilities that are less common elsewhere, such as N-up layouts, word count, PDF metadata editing and adding blank pages.
Where OnCloudPDF is weaker
These are the real limitations of the current tools, taken from their code:
- Compress only re-saves the PDF with an optimized structure. It does not recompress or downsample images, so image-heavy PDFs may barely shrink. It cannot target a size such as 100 KB.
- PDF to Word extracts text into a .docx. Layout, tables and images are not reproduced, and multi-column pages can come out jumbled.
- OCR uses Tesseract in the browser with 8 languages, one per run, and rebuilds the pages from images.
- Unlock does not break passwords and may not decrypt strongly encrypted files.
- PDF/A produces an image-based archival-style copy that is not validated against the PDF/A standard.
- Everything runs in your browser, so very large or image-heavy files depend on your device memory.
How to choose by task
- Confidential documents (contracts, IDs, medical): prefer browser-based or desktop tools; if you use a server-based tool, read its retention policy.
- Shrink a large scanned PDF: a tool with image recompression is needed; use a desktop app or a server-based compressor and check the quality.
- Convert a formatted PDF to an editable Word file: use desktop software or a server-based converter; OnCloudPDF gives you the text only.
- Organize pages (merge, split, extract, reorder, rotate): any approach works; browser-based is the quickest when you do not want to upload.
- Search a scanned document: compare OCR accuracy on a sample page before committing to one tool.
How this comparison was made
The OnCloudPDF column comes from reading the code of each tool (see the individual tool pages). The server-based and desktop columns describe the general approach and avoid provider-specific numbers because they change; for example, PDF24 states that its online tools process files on its servers and that its desktop app keeps files on your PC. Spotted something outdated? Tell us on the contact page.
Frequently asked questions
Is a browser-based PDF tool always more private?
It is more private in one specific way: the file is not sent to a server. It does not encrypt your file or protect it from malware on your own device. You can verify what a site sends by watching the Network tab in your browser developer tools.
What is the best free PDF tool?
There is no single best tool. For private page-level edits, a browser-based tool is a good choice; for layout-faithful conversion or image compression, a desktop app or a server-based service is usually stronger. Pick by task using the table above.
Why does OnCloudPDF not compress images?
The Compress tool only optimizes the internal file structure. Recompressing images needs a different engine, which the site does not include today, so it states that limit openly on the Compress page.