Top API Development Companies for Modern Web and Mobile Apps

Modern digital products run on APIs. They power everything from mobile apps and e-commerce platforms to internal systems, partner integrations, and large-scale enterprise ecosystems. As a CTO, you already know that the strength of your API layer determines how reliably your applications communicate, scale, and evolve.

With businesses moving toward microservices, cloud-native architectures, and real-time digital experiences, choosing the right API development company has never been more critical. You need a team that can design secure, scalable, standards-compliant APIs that work seamlessly across web, mobile, and third-party platforms – without introducing performance bottlenecks or security risks.

This blog highlights the top API development companies trusted by global enterprises for building modern, future-ready API ecosystems. Whether you’re modernizing legacy systems, building new digital products, or expanding integrations, these partners bring the engineering depth and domain expertise needed to deliver APIs that scale with your vision.

Who’s Leading in API Development? Here’s the List

Let’s have a look at the API development firms that stand out for architectural discipline, reliability, and the ability to support modern engineering roadmaps:

 1. Capital Numbers Infotech Limited

• Website: https://www.capitalnumbers.com
• Founded: 2012
• Employees: 500+
• Hourly Rate: <$25/hrdxz
• Notable Clients: Reuters, Tipalti, Cinepolis, Outlook, Isha, Consumer Reports, Nana Elici, DPD, Mphasis, and Stoneacre Motor Group.
• Industry Expertise: Healthcare, banking & finance, real estate, entertainment, manufacturing, and others.
• Awards and Recognitions: Excellence in Artificial Intelligence Solutions (Times Business Award 2025), Growth Leadership in Tech Services (Nasscom, 2025), Best Tech Brands (The Economic Times, 2024), Excellence in IT Services (Times Business Awards, 2024), Clutch Champion (2024), High-Growth Companies – Asia-Pacific (Financial Times, 2023), and others.
• Certifications: ISO 9001 & ISO 27001 and SOC 2 Type II.
• Case Studies: https://www.capitalnumbers.com/case-studies.php
• Headquarters: Kolkata, India
• Contact: info@capitalnumbers.com, +91-33-6799-2222

Capital Numbers is a reputable company that has been serving global clients for more than a decade. This company has won numerous awards and recognitions over the years, demonstrating its dedication and excellence. By choosing them, you can expect top-notch API development and integration services, thereby enhancing your software’s functionality.

Key Services:

• Custom API Development
• API Integration Services
• API Development for Mobile Apps
• Cloud API Integration
• Artificial Intelligence API Solutions
• API Performance Optimization
• API Testing Automation
• API Support & Maintenance
• API-as-a-Service (APIaaS)

Types of APIs They Develop

• Public API
• Partner API
• Internal APIs
• Composite APIs

Reasons to Partner with:

• Over 13 years in the business.
• 300+ glowing five-star ratings on leading B2B review platforms.
• A 500+ strong team covering 50+ technologies.
• Trusted by 250+ clients across the globe.
• 50+ industry awards earned in the last 12 years.
• Agile by default – iterative planning, rapid feedback, continuous delivery.
• Engagement your way: Managed team, staff augmentation, or fixed-cost.
• Expect up to 50% savings on development costs.
• 95% of projects delivered within budget.
• Publicly listed on the BSE.
• Certified quality and security: ISO 9001 & ISO 27001.
• SOC 2 Type II attested controls.
• Two development centers for scale and continuity.
• Access to the top 1% of engineering talent.
• 24/7 post-launch support to maintain system stability.
• Strategic partnerships with Salesforce, Adobe, and Microsoft.
• NDA-backed confidentiality on every engagement.

   2. Astaqc

• Website: https://www.astaqc.com
• Founded: 2015
• Employees: 50+
• Hourly Rate: $25-$49/hr
• Notable Clients: Castor SMS, United Nations, PepsiCo, OldProgrammer, and others.
• Certifications: ISO 9001:2015
• Case Studies: https://www.astaqc.com/case-studies
• Headquarters: Mumbai, India
• Contact: contact@astaqc.com, +91-9892133545

The experts at Astaqc develop cloud-based backends with REST APIs. The objective is to give customers the freedom to access their product on any device, irrespective of the location. In addition to the REST API, they also offer GraphQL development solutions. You can experience the power of real-time data and build scalable and automated GraphQL APIs.

Key Services:

1. REST API Development

• Implementing API Development Services
• Custom API Integration
• API Testing Automation

1. GraphQL API Development

• Automated APIs
• API Design & Architecture
• Data Integration
• API Testing

Reasons to Partner with:

1. Ranked as the No. 1 Software Testing Company and QA Staffing Agency in Mumbai by Clutch.
2. Their team comprises more than 50 members.
3. Total hours worked: 80k.
4. Currently serving 35+ clients.
5. 98% Client Retention Rate.
6. Custom solutions coupled with transparent reports.
7. Their services are agile-ready.
8. Flexible pricing: Modular pricing, professional team, and hourly pricing.

3. Pixel Crayons

• Website: https://www.pixelcrayons.com
• Founded: 2004
• Employees: 675+
• Hourly Rate: <$25/hr
• Notable Clients: Yale University, Infosys, Hitachi, and others.
• Industry Expertise: Healthcare, fintech, and manufacturing.
• Awards and Recognitions: Top Software Development Company and Best Developer in the UK and India (SelectedFirms, 2024), Top Custom Software Developer, Shopify Developer, Python Developer, DevOps Company, and .NET Development Company (TopDevelopers, 2024), Top IoT Development Company (SuperbCompanies, 2024), and others.
• Certifications: CMMI Level 3, ISO, and Great Place to Work.
• Case Studies: https://www.pixelcrayons.com/case-study
• Headquarters: Noida, India
• Contact: +91-965-0185287

If you are looking to transform your digital ecosystem, you can do so with Pixel Crayons exactly in the way you want. Their talented API developers create seamless integrations while addressing your business needs with secure, scalable, and efficient solutions.

Key Services:

• Personalized API Consultation
• API Testing
• API Integration Services
• API for Mobile Apps
• API Automation
• API Configuration & Management
• API Support & Maintenance
• Cloud-based API
• Cross-Platform API Solutions

Reasons to Partner with:

• 20+ years of experience.
• 675+ in-house team.
• 4200+ projects launched.
• 5400+ satisfied customers.
• 100+ agency partnerships.
• Serving clients in 38+ countries.
• 8/5 rating on Clutch and good reviews on other sites.
• Over 24 million leads driven for clients.
• $15 billion revenue driven for clients.
• 97% client retention.
• 3,212,407 hours of expertise.
• Collaborate with the top 1%.
• Free trial, zero overheads, quick setup.
• Excellent code quality and rigorous code review practices.
• Whitelabel partnership.
• Trusted by Fortune 500 companies.
• Flexible hiring models: Dedicated team, team augmentation, or project-based.
• Partner of Microsoft, AWS, and Google Cloud.
• IP rights and NDA protection.
• Language/time-zone compatible stuff.

  4. Aalpha

• Website: https://www.aalpha.net
• Founded: 2008
• Employees: 275+
• Hourly Rate: <$25/hr
• Notable Clients: The World Bank, Securitas, Swiss Re, Pharma Resource Group, Inc., Capsuline, and others.
• Industry Expertise: Agri tech, food & beverage, education, engineering, and others.
• Awards and Recognitions: India’s Best Website Developer (Digital.com, 2021), Top Web Development Partner (Clutch), and others.
• Certifications: ISO 9001:2008 and ISO 9001:2000.
• Case Studies: https://www.aalpha.net/clients/case-studies/?cat=case-studies
• Headquarters: Bengaluru, India
• Contact: contact@aalpha.net, +91-836-426-2222

Aalpha is another top-rated API development company that is helping businesses worldwide with its quality solutions. They have been in this industry for many years and have served several esteemed clients. Their experts leverage the latest technologies when it comes to delivering API solutions.

Key Services:

• Custom API Integrations
• Custom API Development
• API Testing Services
• API Consulting

Reasons to Partner with:

1. Implements superlative agile processes.
2. 900+ clients from SMEs to established brands.
3. 5000+ projects completed in 41+ countries.
4. Engagement models: Time & material, controlled agile, and dedicated team.
5. Save 60% on development cost.
6. Best code practices.
7. Strict NDA.

 5. ScienceSoft

• Website: https://www.scnsoft.com
• Founded: 1989
• Employees: 750+
• Hourly Rate: $50-$99/hr
• Notable Clients: IBM, Walmart, eBay, PerkinElmer, Baxter, and others.
• Industry Expertise: Healthcare, banking, real estate, retail, manufacturing, logistics and transportation, and others.
• Awards and Recognitions: America’s Most Reliable Companies (Statista, 2025), Top 25 Healthcare Software Companies (Healthcare Technology Report, 2025), 116 Healthcare Cybersecurity Companies to Know in 2025 (Becker’s Healthcare), Solution Provider 500 (CRN, 2025), America’s Fastest Growing Companies (Financial Times/Statista, 2025), and others.
• Certifications: ISO 13485, ISO 27001, and ISO 9001.
• Case Studies: https://www.scnsoft.com/case-studies
• Headquarters: McKinney, US
• Contact: contact@scnsoft.com, +1-214-306-6837

With custom API development services, businesses can share data from their custom applications with each other. ScienceSoft is an API development company that always delivers well-documented and safe APIs for your applications.

Key Services:

• API Consulting
• API Design and Implementation
• API Management
• End-to-End API Implementation and Support

Reasons to Partner with:

1. 36 years of expertise.
2. 750+ IT professionals.
3. 4200+ success stories.
4. 30+ industries covered.
5. 1400+ satisfied clients.
6. 8/5 rating on Clutch.
7. Skill-based selection of a project team.
8. Agile delivery.
9. Centralized knowledge management.
10. Better Business Bureau (BBB) accredited business.
11. Offices in several locations.
12. Clients from 80+ countries.
13. 62% of their revenue is generated from contracts that usually last for more than 2 years.
14. Flexible pricing: Fixed price, time and material, consumption-based pricing, and a monthly subscription fee.
15. Partner of AWS and Microsoft Solutions.

 6. OpenXcell

• Website: https://www.openxcell.com
• Founded: 2009
• Employees: 500+
• Hourly Rate: <$25/hr
• Notable Clients: Mondelez International, HealthifyMe, Pinergy, American Express, AVL Systems, and others.
• Industry Expertise: Healthcare, fintech, logistics, retail, and others.
• Awards and Recognitions: Top 15 Software Development Companies (2022), Best Crypto Marketing Firms (2020), and others.
• Certifications: ISO 9001:2008 and CMMI Level 3.
• Case Studies: https://www.openxcell.com/our-work
• Headquarters: Ahmedabad, India
• Contact: sales@openxcell.com

The API professionals at OpenXcell utilize full tech stacks to deliver high-quality products and services. Since their inception, they have been serving multiple industry verticals and boast of having hundreds of satisfied clients.

Key Services:

• API Consulting
• API Design and Implementation
• API Management
• End-to-end API Implementation and Support
• Custom API Development
• Cloud and Intranet API Integration
• API Development for Mobile Apps
• Third-Party API Integration

Reasons to Partner with:

1. 15+ years of development experience.
2. 500+ qualified experts.
3. 1500+ software designed and deployed.
4. 25000 sq. meters of office space.
5. 3 state-of-the-art development facilities.
6. 24/7 IT support staff availability.
7. 1000+ happy customers.
8. Flexible hiring model: Build-operate-transfer, time & material, and fixed cost.
9. 95% client retention.
10. 20% faster product delivery.

7.Moon Technolabs

• Website: https://www.moontechnolabs.com
• Founded: 2009
• Employees: 300+
• Hourly Rate: $25-$49/hr
• Notable Clients: SpendBitcoins, Siemens, Money Club, KVM Tools, and others.
• Industry Expertise: Healthcare, e-learning, fintech, fleet management, real estate, and others.
• Awards and Recognitions: Top Software Developers (IT) in Chicago (Clutch), Top IoT Company in Chicago (Clutch, 2024), Business Excellence Award for WebRTC Innovation (KCCI, 2022), Best Mobile App Development Company (Gesia, 2015), and others.
• Certifications: ISO 27001:2022 and ISO 9001:2015.
• Case Studies: https://www.moontechnolabs.com/portfolios
• Headquarters: Chicago, US
• Contact: sales@moontechnolabs.com, +1-620-330-9814

Moon Technolabs offers custom API development services by leveraging cutting-edge tools. These APIs integrate with your existing systems seamlessly. With their APIs, you can increase the capacity of your legacy systems and transform IT strategies.

Key Services:

• API Consulting Services
• Custom API Development
• Third-Party API Integration
• API Design and Implementation
• API Configuration
• API Support and Maintenance

Reasons to Partner with:

1. 16+ years of experience.
2. 300+ team strength.
3. Expertise in 45+ technologies.
4. 850+ global customers.
5. 1600+ projects completed.
6. 40+ specific industries.
7. 75% locations they serve.
8. 10+ products.
9. Good reviews on various platforms (Clutch, GoodFirms, and Bark)
10. Their applications have been featured in The New York Times, Mashable, The Telegraph, Capterra, and other notable publications.
11. Implements agile processes.
12. Partnerships with AWS, Google Cloud, Microsoft Azure, and several others.
13. Flexible engagement model: Dedicated team, IT consulting, and staff augmentation.

 8. Dotsquares

• Website: https://www.dotsquares.com
• Founded: 2002
• Employees: 1000+
• Hourly Rate: $25-$49/hr
• Notable Clients: Honda, Yankee Candle, Community Fibre, Allurion, Comodo, and others.
• Industry Expertise: Travel & hospitality, media & entertainment, finance, logistics, construction, and others.
• Awards and Recognitions: Forbes Technology Council Official Member (2024), Clutch Champion Spring (2024), Clutch 1000 (2023), Ecommerce Awards (2022), and others.
• Certifications: ISO 27001 and ISO 9001:2015.
• Case Studies: https://www.dotsquares.com/casestudies
• Headquarters: London, UK
• Contact: office@dotsquares.com, +44-208-090-1819

The API developers at Dotsquares possess vast expertise and relevant certifications. They offer outcome-driven API development and integration solutions. If you hire them, you can be assured that your applications will perform well.

Key Services:

• Microservices API Development
• Ecommerce API Development
• Mobile App API Development
• API Modernization and Optimization
• Third-Party API Integration
• Custom API Applications
• Custom API Development
• Strategic API Consultation
• Enterprise API Development
• API-as-a-Service (APIaaS) Solutions
• API Development Support Services

Reasons to Partner with:

1. 23+ years of experience.
2. 1000+ full technical team with expertise in 50+ technologies.
3. 15000+ happy clients.
4. 27000+ successful projects.
5. 6+ offices worldwide.
6. 95% customer satisfaction.
7. 70% average savings on development costs.
8. 1 Global Capability Center (GCC).
9. Served Fortune 500 companies.
10. 5/5 rating on Gartner and HubSpot, 4.6/5 rating on Clutch and Google, and numerous other instances.
11. Agile processes.
12. Hire according to your needs: Bucket hours or dedicated/regular hiring.
13. Partner of Google, Zoho, Microsoft Solutions, and more.
14. They sign an NDA.

 9. Objective

• Website: https://objectiveit.com
• Founded: 1987
• Employees: 10-49
• Hourly Rate: $100-$149/hr
• Notable Clients: MetsaWood, BIFIS, IISS, Spray Tanker Services, SMARTbrief, and others.
• Industry Expertise: Advertising & marketing, automotive, business services, education, and others.
• Awards and Recognitions: Top .NET Developers in England (Clutch, 2025), Top Machine Learning Company in England (Clutch, 2024), and others.
• Certifications: PRINCE2 Certification and Chartered Institute of Marketing (CIM) qualifications.
• Case Studies: https://objectiveit.com/our-work
• Headquarters: Chelmsford, UK
• Contact: interested@objectiveit.com, +44-1245-955-633

Objective offers full-fledged API development solutions that enable systems, applications, and services to work collaboratively. They have been serving multiple industries and have also received many awards and recognitions.

Key Services:

• Custom API Development
• Third-Party API
• API Maintenance and Optimization
• Secure API Development

Reasons to Partner with:

1. Over 35 years of experience.
2. Microsoft partner since 1992.
3. 0 rating on Clutch.
4. Long-term staff retention means you can expect consistent support for your projects.

 10. Apriorit

• Website: https://www.apriorit.com
• Founded: 2002
• Employees: 400+
• Hourly Rate: $100-$149/hr
• Industry Expertise: Cybersecurity, fintech, healthcare, automotive, and others.
• Awards and Recognitions: Clutch 1000 (2024), Official Member of Forbes Technology Council (2024), and others.
• Certifications: ISO 9001, ISO 27001, AWS certified Solutions Architect, TISAX, GDPR, and others.
• Case Studies: https://www.apriorit.com/success-stories/portfolio
• Headquarters: Lynn, USA
• Contact: info@apriorit.com, +1-714-584-0295

Apriorit takes a security-first approach while offering API integration and development services. They implement security measures like authentication and access control, traffic management, data encryption in transit, API gateway implementation, and security testing. Their experts are proficient in building tailored API strategies, selecting the appropriate technologies, and handling and scaling your API ecosystem.

Key Services:

• Custom API Design and Development
• Third-party API Integration
• API Testing
• API Performance Optimization and Troubleshooting

Reasons to Partner with:

1. 23+ years in the business.
2. 400+ tech experts.
3. 675+ completed projects.
4. 20+ R&D labs.
5. 15 development teams.
6. 6 quality assurance teams.
7. Professional research and a reviewing team.
8. Countries represented by clients: 15+.
9. Clients from Fortune 500 companies.
10. Best code quality.
11. 98% client retention.
12. Signs an NDA.

A Practical Guide to Selecting the Right API Development Company

If you want the results you have always desired, choosing an API development partner isn’t a task for the sake of it. Rather, it’s very important since you will be handing over the project to them, and if they aren’t good enough, it’s of no use. So, it’s always better to consider these aspects rather than randomly arrive at a decision:

1. Define your API Needs and Vision: You need to be clear about your API goals. This is the primary requirement. In other words, determine the purpose of the API – whether it’s for enhancing mobile app experiences, integrating with legacy systems, or driving real-time analytics.
2. Assess Technical Expertise: API development is a complex task, and those who do it have to be sound with certain technologies. Hence, you should look for an API development company whose experts excel in REST, GraphQL, or gRPC since these are the technologies required. Also, ensure they understand your tech stack and can manage your current and future performance, security, and scalability needs effectively.
3. Evaluate Experience with Scalability and Security: You can’t afford to neglect security and scalability in API development. If you do, it will be a big blunder. Select a partner who has experience building high-performance APIs that can handle increasing traffic and are protected against DDoS, injection attacks, or data breaches.
4. Check their Integration and Testing Process: Your chosen API development firm must integrate seamlessly with your existing systems. They should also offer thorough unit, integration, and load testing. This is necessary to ensure the API functions as expected under real-world conditions.
5. Request Pilot Projects or Proof of Concept: Before committing, asking for a pilot or proof of concept is always a good idea. This allows you to assess their understanding of your requirements. Moreover, you can evaluate their work quality and determine whether their team collaborates effectively with yours.

Conclusion

Choosing the right API development partner is one of the most important decisions you’ll make for your digital product. The companies highlighted in this guide have proven expertise in building secure, scalable, and future-ready APIs that power modern web and mobile experiences. Whether you’re integrating legacy systems, enabling new mobile features, adopting microservices, or expanding your partner ecosystem, the right team can accelerate delivery while reducing long-term technical risks. As you evaluate your options, focus on architectural depth, security practices, integration experience, and the ability to support your product as it grows. With the right partner, your APIs become a true engine of innovation and scalability.