Software Alternatives & Startups

Userback VS CalcSphere

Compare Userback VS CalcSphere and see what are their differences

Userback

Userback empowers product teams to collect, understand, and act on user feedback with unprecedented speed and clarity.

Rating
0 reviews
Pricing
Freemium Free trial
CalcSphere

70+ free online calculators for EMI, BMI, Zakat, finance, health, math, construction, and unit conversion. No sign-up. Instant results. 100% free.

Rating
0 reviews
Pricing
Free Free trial
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.

Which is more popular?

Based on our record, Userback seems to be more popular. It has been mentioned 3 times since March 2021.

social mentions
3 vs 0
Customer Feedback popularity
100% vs 0%
alternatives listed
240+ vs 40

Base details

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

Userback
CalcSphere
Website userback.io calcsphere.org
Pricing
Freemium Free trial Official pricing
Free Free trial Official pricing
Platforms
Web Browser Google Chrome Firefox Wordpress Internet Explorer Edge Safari +5
—
Company Startup from Australia · 10 - 19 employees —
Listed in

About Userback and CalcSphere

In their own words, as submitted to SaaSHub.

Userback
CalcSphere

Userback is a powerful visual feedback and bug-tracking platform tailored for SaaS teams looking to enhance their product development process. With Userback, you can easily capture and manage user feedback through annotated screenshots, session replays, and customizable surveys. This ensures that...

Read more about Userback

No description of CalcSphere yet.

Features and specs

What each product offers, as listed by its team.

Userback 14 features
CalcSphere 5 features
  • Screenshot Capturing
  • Screen Recording
  • Annotations
  • Integrations
  • Collaboration Tools
  • Clean UI
  • Customizable
  • Feedback widget
  • Feedback & Commenting
  • Free Trial
    14-day free trial, no credit card required
  • GDPR Compliant
  • Browser Extensions
  • Branding
  • Surveys
  • Free to use
    CalcSphere appears to be a free online calculator and math tool platform, making it accessible to students, educators, and professionals without any cost barrier.
  • Web-based accessibility
    As a web-based platform, CalcSphere can be accessed from any device with a browser and internet connection, without requiring software installation.
  • Multiple calculator types
    The platform offers a variety of calculators and mathematical tools covering different areas, providing users with a one-stop resource for various computation needs.
  • User-friendly interface
    The site is designed with a clean and straightforward interface, making it relatively easy for users to find and use the calculators they need.
  • Educational utility
    CalcSphere can serve as a helpful educational resource for students learning math and related subjects, providing quick computation and verification of answers.

Possible disadvantages

  • Limited brand recognition
    CalcSphere is not as widely known or established as major calculator platforms like Wolfram Alpha, Desmos, or Symbolab, which may lead to lower user trust and a smaller community.
  • Limited advanced features
    Compared to more established platforms, CalcSphere may lack advanced computational capabilities such as symbolic algebra, complex graphing, or step-by-step solution breakdowns.
  • Sparse documentation and support
    As a smaller platform, CalcSphere may have limited documentation, tutorials, or customer support options compared to larger, more established competitors.
  • Internet dependency
    Being entirely web-based means users cannot access CalcSphere's tools offline, which can be a limitation in areas with unreliable internet connectivity.
  • Uncertain long-term reliability
    As a lesser-known platform, there may be concerns about its long-term maintenance, updates, and availability compared to tools backed by larger organizations or companies.

Analysis

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

Userback
CalcSphere

Overall verdict

  • Userback is considered a strong choice for teams looking for an easy-to-use and efficient feedback solution. Its visual feedback features are particularly valuable for identifying and resolving issues quickly. However, the suitability of Userback might depend on the specific needs and workflows of your team.

Why this product is good

  • Userback is a feedback and bug reporting tool that integrates directly with your website or product, offering a simplified process for capturing user feedback, suggestions, and bug reports. It provides visual feedback tools, such as screenshot and annotation capabilities, which enhance communication between users and developers. The platform also supports seamless integration with popular project management and communication tools, making it efficient for teams to address feedback.

Recommended for

  • Web development teams looking to gather focused feedback during development.
  • Product teams seeking a streamlined method for collecting user insights.
  • Businesses that need a tool to easily manage and act on customer feedback and bug reports.

Overall verdict

  • I don't have reliable information about CalcSphere (calcsphere.org), so I can't verify whether it's a good or trustworthy service. Please research it independently before relying on any assessment.

Why this product is good

  • I cannot find verified details about this specific website's features, reputation, or reliability
  • Any positive claims I might make would be unsubstantiated and potentially misleading
  • Legitimate services typically have verifiable reviews, clear ownership, and established track records you can check
  • You should look for independent user reviews, security indicators (HTTPS, privacy policy), and third-party ratings before trusting it

Recommended for

  • Users who first verify the site's legitimacy through independent reviews and research
  • People who confirm the service meets their specific needs after testing it cautiously
  • Anyone who checks for security and privacy protections before sharing personal or financial information

Videos

Walkthroughs and reviews on video.

Userback 1 video + Add
CalcSphere 0 videos + Add

Userback Explainer Video

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

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
Userback
CalcSphere
100% 100%
0% 0%
0% 0%
100% 100%
100% 100%
0% 0%
0% 0%
100% 100%

Questions & Answers

As answered by people managing Userback and CalcSphere.

What makes your product unique?

Userback's answer

Userback stands out due to its emphasis on visual feedback and seamless integration into existing workflows. Unlike traditional feedback tools, Userback allows users to capture annotated screenshots, session replays, and detailed user insights directly from your website or application. This level of visual detail makes it easier for teams to understand and address issues quickly. Additionally, Userback's integrations with popular project management tools like Jira, Trello, Asana, and Slack ensure that feedback is instantly actionable, keeping your development process efficient and user-focused.

CalcSphere's answer:

  • Zakat Calculator with Pakistani Fatwa — The only free Zakat calculator following the silver nisab ruling of Mufti Taqi Usmani (Fiqhi Muqalat Vol 1, Page 31) and Darul Uloom Karachi. Silver nisab is pre-selected by default for mixed assets.

  • Multi-currency support with live rates — All finance calculators support PKR, USD, EUR, GBP, AED and 7 more currencies with live exchange rates from open.er-api.com

  • 70+ calculators in one place — Finance, health, math, construction, unit converters and date tools all under one clean interface

  • Construction calculators for Pakistan — Concrete volume, bricks, paint, tiles, steel weight and construction cost per marla — built for Pakistani builders and engineers

  • 100% free, no sign-up, no ads blocking the calculator — All calculations run locally in your browser. No data is stored or sent to any server.

  • Perfect PageSpeed scores — 100/100 Performance, 100/100 SEO, 100/100 Best Practices on Google PageSpeed Insights

Why should a person choose your product over its competitors?

Userback's answer

Userback offers a unique combination of visual feedback tools, customizable user surveys, intuitive user experience, and powerful integrations that set it apart from competitors. The platform's ability to capture detailed, visual feedback directly from users reduces the back-and-forth often associated with bug tracking and issue resolution. Moreover, Userback's customizable feedback forms and automated workflows make it easy to tailor the platform to your specific needs, whether you're a small team or a large organization. By choosing Userback, you ensure that your development process is driven by clear, actionable insights that lead to better products and happier users.

CalcSphere's answer:

  • No clutter — Unlike calculator.net and rapidtables.com, CalcSphere puts the calculator first with no pop-ups, no distracting ads blocking the tool, and instant results

  • Mobile-first design — Built with Next.js 14 and Tailwind CSS, CalcSphere loads in under 1 second on mobile (LCP 1.3s) — faster than most competitor sites

  • Dark and light mode — Clean modern UI with full dark mode support unlike most legacy calculator sites

  • Dropdown inputs — No need to type unit abbreviations manually — all unit converters use dropdown selection

  • Rich explanations — Every calculator includes a "What is" section, step-by-step how-to guide, pro tips, and real-world use cases — not just a bare calculator

  • Pakistan-specific tools — Zakat calculator, construction cost per marla, PKR salary calculator and EMI calculator built for Pakistani users — not available on international competitors

How would you describe the primary audience of your product?

Userback's answer

Userback’s primary audience includes product managers, UX/UI designers, software developers, and customer support teams in SaaS companies and digital agencies. These professionals rely on Userback to streamline the feedback collection process, improve communication between teams, and deliver products that align with user expectations. Whether working on a new feature or refining an existing product, Userback helps these teams stay connected with their users and make data-driven decisions that enhance the overall user experience.

CalcSphere's answer:

CalcSphere serves four main audiences:

  • Pakistani users — Professionals, students and homeowners calculating EMI, Zakat, construction costs, salaries and inflation in PKR

  • UK and international business users — Small business owners calculating business loan repayments, VAT, stamp duty and retirement planning

  • Students and academics — Math and science students using percentage, GPA, quadratic solver, square root and fraction calculators

  • Health and fitness enthusiasts — People tracking BMI, calorie deficit, body fat, ideal weight and running pace

CalcSphere is used in 80+ countries with strongest traffic from Pakistan, United Kingdom, United States, Australia, South Africa and Malaysia.

What's the story behind your product?

Userback's answer

Userback was born out of a desire to bridge the gap between users and product teams by making feedback collection more efficient and actionable. The founders recognized that traditional feedback tools often lacked the ability to convey the visual context needed to truly understand user issues. To solve this, they created a platform that combines visual feedback with powerful integrations, allowing teams to capture, manage, and act on feedback in real-time. Since its inception, Userback has grown into a trusted tool for thousands of teams worldwide, helping them build products that users love.

CalcSphere's answer:

CalcSphere was built out of frustration with existing calculator websites — most are cluttered with ads, slow to load, and don't serve non-US audiences well.

The goal was simple: build the fastest, cleanest, most accurate free calculator website that works for everyone — from a Pakistani homeowner calculating construction costs to a UK small business owner planning a loan.

The Zakat calculator was a particularly important addition. Most online Zakat calculators use incorrect nisab values or don't explain which scholarly standard they follow. CalcSphere's Zakat calculator is built on the verified fatwa of Mufti Taqi Usmani (Fiqhi Muqalat Vol 1, Page 31) and defaults to silver nisab for mixed assets — making it the most accurate free Zakat calculator available online.

Built with Next.js 14, Tailwind CSS and deployed on Vercel, CalcSphere launched in April 2026 and achieved 100/100 Google PageSpeed scores on both mobile and desktop.

Who are some of the biggest customers of your product?

CalcSphere's answer:

  • CalcSphere is a free tool used by individual users worldwide — not a B2B SaaS product with named customers

  • Users include students, homeowners, small business owners, construction contractors, financial planners and Muslim professionals calculating Zakat

  • Active users in 80+ countries including Pakistan, United Kingdom, United States, Australia, India, South Africa, Malaysia and Bangladesh

Which are the primary technologies used for building your product?

CalcSphere's answer:

  • Next.js 14 (App Router) — React framework for server-side rendering and static generation
  • Tailwind CSS — Utility-first CSS framework for responsive design
  • Vercel — Deployment and hosting with global CDN
  • open.er-api.com — Live currency exchange rates API
  • JSON-LD Schema — Structured data for Google rich results (WebApplication, FAQPage, BreadcrumbList, HowTo)
  • Google Analytics 4 — Traffic and engagement tracking
  • Porkbun — Domain registrar for calcsphere.org

User comments

Share your experience with using Userback and CalcSphere. For example, how are they different and which one is better?

Log in or Post with

Social recommendations and mentions

Recommendations tracked on public social media and blogs since March 2021.

Userback 3 mentions
CalcSphere 0 mentions
  • What is Userback and how does it work?
    Userback is a game changer! It lets me collect feedback from my users in a snap and share it with my dev team so we can fix things faster. It's saved so many headaches from figuring out where to get started by having everything in one... Source: over 3 years ago
  • Web designers of reddit, how do you effectively do remote design reviews?
    Userback is a good tool for design review & feedback. Source: about 4 years ago
  • Received an Admiral anti-adblock popup despite uBlock Origin installed and annoyance filters enabled
    The userback.io link appears to relate to the site's hovering "feedback" button on the side, which may be regarded by some as an annoyance, though I'd only block it if it doesn't otherwise remove the feedback function on the site. The... Source: about 4 years ago

Tracking CalcSphere since Jun 2026.

Alternatives to Userback and CalcSphere

When comparing Userback and CalcSphere, you can also consider the following products.