Software Alternatives, Accelerators & Startups

ALTCHA VS Smallpdf

Compare ALTCHA VS Smallpdf and see what are their differences

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ALTCHA logo ALTCHA

ALTCHA is a free CAPTCHA alternative that uses a proof-of-work mechanism to protect your website, and online services from spam.

Smallpdf logo Smallpdf

PDF document management and conversion suite
  • ALTCHA Simple, user-friendly verification.
    Simple, user-friendly verification. //
    2024-04-30

ALTCHA uses a proof-of-work mechanism to protect your website, APIs, and online services from spam and unwanted content. Unlike other solutions, ALTCHA is free, open-source and self-hosted, without external services, does not use cookies nor fingerprinting, does not track users, and is fully compliant with GDPR.

  • Smallpdf Landing page
    Landing page //
    2023-09-21

ALTCHA

Website
altcha.org
Pricing URL
-
$ Details
free
Platforms
Web REST API

ALTCHA features and specs

  • Privacy-friendly, GDPR compliant
    No cookies, no tracking, no external servers.
  • Frustration-free
    No visual puzzles. PoW Captcha is better for people.
  • Spam Filtering
    Employs machine learning to categorize submitted data and identify unwanted messages.
  • Open-source
    Free to use, free to modify. MIT licensed.

Smallpdf features and specs

  • User-Friendly Interface
    Smallpdf provides a clean, intuitive, and easy-to-navigate interface, making it accessible for users of all technical levels.
  • Wide Range of Tools
    Offers a variety of tools for PDF editing, including compressing, merging, splitting, and converting PDFs to other formats.
  • Cloud Integration
    Seamlessly integrates with cloud storage services like Google Drive and Dropbox, allowing users to work directly with their files stored online.
  • Security
    Utilizes strong encryption and deletes files from their servers after one hour, ensuring user data is kept secure and private.
  • Cross-Platform Availability
    Accessible from various devices including desktops, tablets, and smartphones with responsive web design.
  • Free Tier
    Provides a free tier with limited features, which is suitable for occasional or basic users.

Possible disadvantages of Smallpdf

  • Limited Free Features
    The free version only allows for two tasks per day and places restrictions on larger files and advanced features, leading to potential inconvenience for frequent users.
  • Subscription Cost
    The premium subscription can be considered expensive for some users, particularly those who only need occasional PDF edits.
  • File Size Limit
    Even with a premium subscription, there are restrictions on the maximum file size that can be uploaded and processed.
  • Internet Dependence
    Requires an active internet connection to use most of its features, which can be a limitation for users with unreliable or slow connectivity.
  • Privacy Concerns
    Despite strong encryption, some users may still have reservations about uploading sensitive documents to an online service.
  • Limited Customization
    The range of customization options for certain tools may be limited compared to more specialized PDF software.

Analysis of Smallpdf

Overall verdict

  • Smallpdf is a reliable and efficient tool for managing PDF documents, suitable for both casual users and professionals. Its combination of versatility, ease of use, and security features makes it a strong contender in the realm of online PDF services.

Why this product is good

  • Smallpdf is considered good because it offers a wide range of PDF tools that are easy to use and accessible online. It provides functionalities such as PDF conversion, compression, editing, and signing, all within a user-friendly interface. This makes it an ideal choice for both individuals and businesses looking for efficient document management solutions. Additionally, it emphasizes security by ensuring encrypted file transfers, which is crucial for handling sensitive information.

Recommended for

  • Individuals who frequently work with PDFs and need a straightforward tool for conversions, compressions, or edits.
  • Students who need to annotate and organize their study materials in a PDF format.
  • Professionals who require a reliable tool for signing documents and collaborating with team members remotely.
  • Businesses looking for secure document management solutions with the flexibility of online access.

ALTCHA videos

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

Add video

Smallpdf videos

smallpdf tutorial video

More videos:

  • Review - Smallpdf Review
  • Tutorial - Smallpdf | How to do Unlimited Free Conversions ? | Hack for Smallpdf | Bypass limit of 2 conversion

Category Popularity

0-100% (relative to ALTCHA and Smallpdf)
SPAM Protection
100 100%
0% 0
PDF Tools
0 0%
100% 100
Captcha
100 100%
0% 0
PDF Converter
0 0%
100% 100

Questions & Answers

As answered by people managing ALTCHA and Smallpdf.

What makes your product unique?

ALTCHA's answer

What makes ALTCHA unique is that it is free, open-source and self-hosted, without external services, does not use cookies nor fingerprinting, does not track users, and is fully compliant with GDPR. Unlike other captcha solutions, ALTCHA does not require users to solve puzzles or captchas and uses a proof-of-work mechanism instead.

Why should a person choose your product over its competitors?

ALTCHA's answer

Here are some key reasons why a person should choose ALTCHA over its competitors:

  • Privacy compliance - ALTCHA is fully compliant with privacy regulations like GDPR since it does not use cookies, fingerprinting or track users. This is a major advantage over other captcha solutions.
  • Open source and self-hosted - ALTCHA is free, open source software that can be self-hosted without relying on external services. This gives more control and independence to the user.
  • Accessible design - ALTCHA uses a proof-of-work mechanism instead of puzzles or captchas, making it more friendly and accessible for humans. Captchas can be difficult for some users.
  • Machine compatibility - ALTCHA is designed to also work for machines and APIs, making services accessible for bots and automated systems. Other solutions may not be as compatible.
  • Modern approach - ALTCHA represents a privacy-first, inclusive approach to spam protection as opposed to traditional captcha methods. This future-proofs the solution.
  • Effective spam filtering - In addition to proof-of-work, ALTCHA also offers an effective spam filter module to block sophisticated spam attacks. This provides comprehensive protection.

So in summary, ALTCHA's privacy compliance, open design, accessibility, machine compatibility and modern approach give it clear advantages over competing captcha solutions.

Which are the primary technologies used for building your product?

ALTCHA's answer

JavaScript and Svelte.

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare ALTCHA and Smallpdf

ALTCHA Reviews

We have no reviews of ALTCHA yet.
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Smallpdf Reviews

Best Free Alternatives to Adobe Acrobat in 2026
Smallpdf is a well-known online PDF platform with a clean interface. It works entirely in the browser and integrates with Google Drive and Dropbox, making it convenient if you store files in the cloud. The free tier limits you to two tasks per hour and adds a watermark on some output files. Files are uploaded to Smallpdf's servers for processing.
Best Online Image Converters in 2026: Docpose.cloud Leads the Pack
Users highlight Docpose.cloudโ€™s reliabilityโ€”no failed conversions even on rare formats. CloudConvert gets praise for quality tweaks but frustrates with daily resets. iLoveIMG is loved for extras like AI, but free limits irk. Smallpdf suits PDF-image hybrids, less pure images. Convertio is straightforward but caps freebies quick.
Source: fileproinfo.com
Ever wondered why bank statements are always in PDF?
Platforms like iLovePDF and Smallpdf are among the most popular choices. They do a decent job for simple PDFs, but I quickly realized a few issues:
Source: medium.com
Top 10 PDF Converters for converting to or from PDF effortlessly
Smallpdf is one of the most well-known PDF converter tools online. Offering a simple, user-friendly interface, it allows users to convert files to and from PDF without any hassle. Smallpdf supports over 18 file types and integrates with Google Drive and Dropbox for easy cloud storage access.
The 13 Best Free PDF Editors (February 2024)
One of the quickest ways to add images, text, shapes, or your signature to a PDF is with Smallpdf. I find it extremely easy to use for those things, but I opt for one of the editors that top this list if I need to edit the text because this one won't do it for free.

Social recommendations and mentions

Based on our record, Smallpdf seems to be a lot more popular than ALTCHA. While we know about 38 links to Smallpdf, we've tracked only 3 mentions of ALTCHA. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

ALTCHA mentions (3)

  • A self-hosted Google reCAPTCHA alternative (we ship it)
    The captcha on orkestr is Altcha. Self-hosted, no third-party JS, no Google, no behavioral tracking. Users don't see a puzzle. There's a single checkbox and a quiet "verifying..." while the browser does some math. About a second, total. - Source: dev.to / 2 months ago
  • Why Proof-of-Work Beats CAPTCHA for Form Protection
    Here's how PoW works for form protection (using the ALTCHA wire format):. - Source: dev.to / 4 months ago
  • Wicketkeeper โ€“ privacy-friendly, self-hostable PoW CAPTCHA
    Go based, similar to JS based ALTCHA https://altcha.org/ discussed at https://news.ycombinator.com/item?id=43971068. - Source: Hacker News / 7 months ago

Smallpdf mentions (38)

  • OpenDataLoader: Safe, Open, High-Performance โ€” PDF for AI
    According to statistics from smallpdf.com, by 2025, there will be a massive 2.5 trillion PDF documents stored worldwide, and 290 billion new PDF documents will be created every year. - Source: dev.to / 7 months ago
  • Stirling-PDF: local web application to perform various operations on PDFs
    Smallpdf [1] probably deserves a mention here. Not OSS and not self-hosted, but Iโ€˜ve used it occasionally and it has always worked really well. When I was running an agency, we inherited their first office โ€“ very cool folks. [1] https://smallpdf.com/. - Source: Hacker News / over 2 years ago
  • Looking fore college ruled template to print
    And use this one to merge two single-page pdf to make a double side page. Source: over 2 years ago
  • PDF to Excel without O365/Adobe Acrobat?
    I don't have Office 365 for the "Get Data" option, nor do I have Adobe Acrobat. I've tried the smallpdf website but it came out a mess, possibly because my original spreadsheet had highlighted rows and lots of text in some of the cells. Source: about 3 years ago
  • 5 tips to improve your SaaS user onboarding
    Examples of companies doing this well: - SmallPDF users can convert or compress a limited number of files without an account โ€” turning users into advocates and customers once paid use cases comes along; - Freshline uses interactive product demos to help users self-educate and understand the value of their features, without a paywall or registration;. Source: over 3 years ago
View more

What are some alternatives?

When comparing ALTCHA and Smallpdf, you can also consider the following products

reCAPTCHA - reCAPTCHA is a free security service that protects your websites from spam and abuse.

iLovePDF - Premium online PDF tool set

hCaptcha - Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.

Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.

Cloudflare Turnstile - Cloudflare's service for any company to replace CAPTCHAs and deliver a better experience to web visitors.

Sejda - Split, merge and other powerful PDF tools.