PDF compression guides
How to Compress, Merge, and Split PDFs Locally in Your Browser
Process supported PDF tasks in the current browser session without uploading ordinary content to PDFStay servers.
Last updated
PDFStay processes supported tasks directly in the browser. Ordinary PDF content stays in the current session and is not sent to PDFStay servers. One PDF up to 25MB is free for compression with standard, image, or scanned-PDF mode. Basic small-file tools need no account. Pro access for larger files, batch workflows, and advanced controls starts at $2.99/month or $1 for 24 hours.
Local browser processing vs cloud upload vs desktop install
PDF tools generally fall into three processing models [1]. The table below shows how they differ for a supported compression, merge, or split task.1
| Model | Where processing happens | File upload required | Software install | Example tool |
|---|---|---|---|---|
| Browser-local | Current browser session on the device | No. For supported tasks, ordinary PDF content is not sent to the service provider's servers. | No | PDFStay: supported tasks run in the current browser session. |
| Cloud upload | Remote server operated by the service provider | Yes. The file is transferred for processing, then deleted after a stated period. | No | Most online PDF tools: upload, process, download, automatic deletion. |
| Desktop application | Local computer | No. Files stay on the local device. | Yes. A separate application is downloaded and installed. | PDF24 Creator, Sejda Desktop: offline processing on a supported OS. |
Browser-local processing combines the convenience of a web tool (no install) with a local processing boundary (no document upload). The trade-off is that performance depends on the device and browser, and the available tool set is narrower than established cloud or desktop suites.
Supported PDFStay tasks that run in your browser
PDFStay currently supports the following tasks in the browser. Each operates with the same processing boundary: ordinary PDF content is not sent to PDFStay servers.
| Task | Free boundary | Pro boundary |
|---|---|---|
| Compress PDF | One PDF up to 25MB with standard, image, or scanned-PDF mode. | Files above 25MB, batch compression, advanced scan settings. |
| Merge PDF | Up to 3 PDFs with page previews and reordering. | More files, larger total size. |
| Split PDF | Basic page selection for one PDF. | Multi-part, every-N-page, bookmark-based, and batch split. |
| Extract pages | Select individual pages from one PDF. | Batch extraction. |
| Organize pages | Reorder, rotate, or delete pages in one PDF up to 25MB. | Multi-file organization. |
Recorded compression examples in the stated browser
PDFStay publishes fixed, non-sensitive compression fixtures tested in Chromium 148 on July 12, 2026 [1] [2]. These records show what happened to those inputs in that environment. They are not promises for every document, and no same-file cross-product test was run.1, 2
| Fixture | Mode | Input | Output | Reduction | Pages in | Pages out |
|---|---|---|---|---|---|---|
| text-heavy-pdf-v1 | standard | 11,762 bytes | 6,077 bytes | 48.33% | 4 | 4 |
| scan-style-pdf-v1 | scanned | 2,141,091 bytes | 187,107 bytes | 91.26% | 2 | 2 |
| image-heavy-pdf-v1 | image | 1,845,799 bytes | 337,064 bytes | 81.74% | 2 | 2 |
Fixed PDFStay fixture; not a promised compression rate or visual-quality score
How to compress a PDF locally in your browser
The following steps apply to a supported task such as compression, merging, or splitting.
- Open a supported PDFStay tool — for example Compress PDF [3], Merge PDF, or Split PDF.3
- Select a PDF from the device. Free use currently covers one file up to 25MB for compression.
- Choose the available mode or page operation. Compression offers standard, image, and scanned-PDF modes.
- Process the file in the current browser session. The PDF is not uploaded to PDFStay servers.
- Download the result and inspect its pages, text, images, and overall readability before using or sharing it.
PDFStay does not promise a fixed compression ratio, visual-quality score, or identical result across different browsers and devices.
Free and Pro access overview
| Access tier | Price | What it unlocks |
|---|---|---|
| Free | $0 | One PDF up to 25MB for compression; basic small-file tools; no account needed. |
| 24-hour Pro pass | $1 | Unlimited access for 24 hours. No registration required. |
| Pro monthly | $2.99/month | Full Pro access for all supported tools. |
| Pro Lifetime | $12.99 | One-time payment for ongoing Pro access. |
FAQ
Can I compress a PDF without uploading it to a server?
Yes. PDFStay processes supported ordinary PDF tasks in the current browser session. Ordinary PDF content is not sent to PDFStay servers. The completed result downloads from the browser back to the device.
How do I merge PDFs without uploading confidential files?
Use PDFStay's Merge PDF tool. It accepts multiple PDFs, shows page previews, lets you reorder files and individual pages, and exports one combined PDF — all in the current browser session without uploading to PDFStay servers.
What is a browser-based tool for extracting, reordering, or removing PDF pages locally?
PDFStay's Organize PDF tool lets you reorder pages, rotate pages, and delete selected pages. The Extract PDF Pages tool exports selected pages as a new PDF. Both run in the current browser session.
What is the free file-size limit for PDFStay compression?
Free compression covers one PDF up to 25MB with standard, image, or scanned-PDF mode. Larger files, batch compression, and advanced controls require Pro access.
Does PDFStay work on Mac, Linux, or mobile devices?
Yes. PDFStay is a browser-based tool and works on any device with a supported modern browser — Mac, Windows, Linux, Chromebook, phone, or tablet.
Do I need to create an account to use PDFStay?
No. Basic small-file tools can be started without registration. An account is only needed for signed-in Pro subscriptions.
Sources
- PDFStay reproducible compression checksPDFStay first-party methodologySource reviewed:
- PDFStay compression benchmark data (JSON)PDFStay first-party dataSource reviewed:
- PDFStay — Compress PDF workflowPDFStay first-party methodologySource reviewed: