Software Alternatives & Startups

upub.app VS CloudLinux

Compare upub.app VS CloudLinux and see what are their differences

upub.app

upub turns fixed PDF pages — including scans — into reflowable EPUB text. Change the font size on Kindle, Kobo or your phone without zooming, panning or losing your place.

Rating
0 reviews
Pricing
Paid $4.99 / One-off (1,000 page-credits)
CloudLinux

Making Linux secure, stable, and profitable for thousands of hosting providers and data centers worldwide.

Rating
0 reviews
Pricing
Open source
Note: These products don't have any matching categories. If you think this is a mistake, please edit the details of one of the products and suggest appropriate categories.

Base details

Website, pricing, platforms and company facts side by side.

upub.app
CloudLinux
Website upub.app cloudlinux.com
Pricing
Paid $4.99 / One-off (1,000 page-credits) Official pricing
Open source
Platforms
Web
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Company Startup from Turkey · 1 - 9 employees · 2026 —
Listed in

About upub.app and CloudLinux

In their own words, as submitted to SaaSHub.

upub.app
CloudLinux

upub turns fixed PDF pages into real, reflowable EPUB text. Instead of shrinking a paper page onto a six-inch screen, it rebuilds the book: reading order, chapters, headings, footnotes and images. Running headers and page numbers are removed from the text flow. Scanned PDFs are supported through...

Read more about upub.app

No description of CloudLinux yet.

Features and specs

What each product offers, as listed by its team.

upub.app 3 features
CloudLinux 5 features
  • Scanned PDF support
    AI-assisted OCR turns page images into real, resizable text
  • Per-page quality report
    Every page is confidence-scored; uncertain pages are flagged, no silent errors
  • 23 e-reader profiles
    Tuned output for Kindle, Kobo (KEPUB), Apple Books, PocketBook, Boox and reMarkable
  • Enhanced Server Stability
    CloudLinux uses its lightweight virtualization technology (LVE) to isolate each tenant on a shared hosting server, preventing any single user from consuming excessive resources and crashing the server for everyone else. This ensures consistent uptime and performance.
  • Improved Security with HardenedPHP and KernelCare
    CloudLinux offers HardenedPHP, which patches old and unsupported PHP versions against known vulnerabilities, and KernelCare, which provides live kernel patching without requiring server reboots. These features significantly enhance server security posture.
  • Resource Limit Management
    Administrators can set granular resource limits (CPU, memory, I/O, number of processes, etc.) per user account using LVE Manager. This makes it easy to manage shared hosting environments and ensure fair resource distribution among tenants.
  • CageFS File System Virtualization
    CageFS creates a virtualized file system for each user, preventing them from seeing other users on the server, viewing sensitive configuration files, or exploiting server vulnerabilities. This adds an important layer of isolation and security.
  • Wide Compatibility with Hosting Panels
    CloudLinux integrates seamlessly with popular hosting control panels such as cPanel, Plesk, and DirectAdmin, making it straightforward for hosting providers to adopt without overhauling their existing infrastructure or workflows.

Possible disadvantages

  • Additional Licensing Cost
    CloudLinux requires a paid monthly or annual license on top of the base server cost. For smaller hosting providers or individual server owners, this additional expense can add up and may not always be justifiable compared to free alternatives.
  • Limited to CentOS/RHEL-Based Systems
    CloudLinux is built on top of RHEL/CentOS and does not support other Linux distributions like Ubuntu or Debian. This limits its adoption for hosting providers who prefer or already run non-RHEL-based environments.
  • Learning Curve for Configuration
    While CloudLinux provides powerful resource management tools, properly configuring LVE limits, CageFS, PHP Selector, and other features requires a solid understanding of the platform. Misconfiguration can lead to users being unnecessarily restricted or resources being poorly allocated.
  • Potential Performance Overhead
    The additional layers of virtualization, resource monitoring, and file system isolation introduced by CloudLinux can impose a slight performance overhead on the server compared to running a bare, unmodified Linux distribution without these controls.
  • Dependency on CloudLinux Ecosystem
    Adopting CloudLinux means relying on their ecosystem for kernel updates, PHP patches, and security fixes. If the company experiences delays in releasing patches or changes its pricing/licensing model, hosting providers may find themselves locked into a dependency that is difficult to migrate away from.

Analysis

An editorial look at what each product does well and who it suits.

upub.app
CloudLinux

No analysis of upub.app yet.

Overall verdict

  • CloudLinux is a well-regarded, mature Linux OS distribution and toolset specifically designed for shared hosting and multi-tenant server environments, offering strong isolation, resource management, and security features that make it a solid choice for hosting providers.

Why this product is good

  • Provides LVE (Lightweight Virtual Environment) technology for per-tenant resource isolation, preventing 'bad neighbor' effects on shared servers
  • Enhances server stability and security by isolating users so that one account's issues (crashes, resource spikes) don't affect others
  • Offers extended lifecycle support (longer than standard CentOS/RHEL support windows), which is valuable for legacy systems
  • Includes tools like CloudLinux OS Shield, Imunify360 integration, and hardened kernel options for improved security
  • Compatible with popular control panels like cPanel and Plesk, making it easy to integrate into existing hosting stacks
  • Backed by an established company with a long track record in the hosting industry and responsive support
  • Offers granular control over CPU, memory, I/O, and other resources per user account
  • Provides PHP Selector and multiple PHP version support, useful for hosting providers serving diverse client needs

Recommended for

  • Web hosting companies running shared or reseller hosting environments
  • Hosting providers needing to isolate customer accounts on the same physical server
  • Businesses requiring extended OS support lifecycles beyond standard RHEL/CentOS EOL dates
  • Enterprises using cPanel or Plesk that want tighter security and resource control
  • Hosting companies looking to reduce support tickets caused by noisy-neighbor resource contention
  • IT teams managing multi-tenant infrastructure who need governance and monitoring tools built into the OS layer

Videos

Walkthroughs and reviews on video.

upub.app 0 videos + Add
CloudLinux 3 videos + Add

No upub.app videos yet. You could help us improve this page by suggesting one.

When To Use Cloudlinux On Your Virtual Private Server (VPS)

More videos

  • - CloudLinux OS+ in a minute: Explore Features
  • - How CloudLinux Plans to Keep CentOS 6 Alive

Category popularity

How often each product is chosen within a category, 0–100% relative to the other.

Score bands 0–20 21–40 41–50 51–60 61–100
upub.app
CloudLinux
100% 100%
0% 0%
0% 0%
100% 100%
100% 100%
0% 0%
0% 0%
100% 100%

Questions & Answers

As answered by people managing upub.app and CloudLinux.

What makes your product unique?

upub.app's answer

  • Rebuilds the book, not just the file: reading order, chapters, headings, footnotes and images are reconstructed; running headers and page numbers are removed from the text flow.
  • Handles scanned PDFs: AI-assisted OCR turns page images into real, resizable text.
  • No silent errors: every page gets a confidence score, and uncertain pages are flagged in a downloadable quality report.
  • Device-aware output: 23 e-reader profiles, including native KEPUB for Kobo.

Why should a person choose your product over its competitors?

upub.app's answer

Most converters, online tools and even Calibre mostly extract characters and guess where paragraphs belong. With complex or scanned PDFs, the result is broken lines, page numbers inside sentences, or pages that stay as tiny images.

upub analyzes the page layout first, then packages a validated EPUB 3. It also tells you which pages it is unsure about, instead of hiding mistakes.

Pricing is pay once: credit packs from $4.99 for 1,000 pages, no subscription, and credits never expire.

How would you describe the primary audience of your product?

upub.app's answer

E-reader owners (Kindle, Kobo, PocketBook, Boox, reMarkable) who have books, papers or course material only as PDFs, including scans, and are tired of zooming and panning on a small screen. Students, researchers and avid readers in any language, including right-to-left and CJK scripts.

What's the story behind your product?

upub.app's answer

upub started as a tool for one reader. A close friend had many books only as PDFs made for A4 paper, and on her e-reader she had to zoom, drag sideways and find her line again after every move. Existing converters flattened the books into screenshots, dropped headings and scrambled footnotes. So I wrote her a converter that understood the layout and returned a real EPUB with her font, her size and chapters where chapters belong. She read three books that week and said: "Don't keep this to yourself." upub is that same tool, now for everyone stuck with a PDF.

Which are the primary technologies used for building your product?

upub.app's answer

Python, FastAPI, PostgreSQL, Google Gemini (layout analysis and OCR), pdftext and PDFium for PDF parsing, Next.js with Tailwind CSS for the web app, Docker, and Polar for payments. Output is validated with W3C EPUBCheck.

Who are some of the biggest customers of your product?

upub.app's answer

My Girlfriend :)

User comments

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Alternatives to upub.app and CloudLinux

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