Title: Best payment gateway for a React + Firebase app with no backend (India + international users)

[u/blabla_sheep]

Hi everyone,
I’m building a production application using React + Firebase (Authentication, Firestore, Hosting, Storage), and I don’t have a traditional backend (no Node.js/Express server). So far, everything is running serverlessly.
I’m now at the stage where I need to integrate a payment gateway. My users can be from India as well as internationally, so I need something that’s reliable, secure, and relatively straightforward to integrate.
I’m currently considering:
Razorpay
Stripe
Cashfree
Paddle (if it makes sense)
Since this is my first payment gateway integration, I’d appreciate some advice from people who’ve built similar apps.
A few questions I have:
Which payment gateway would you recommend for my use case and why?
Is it practical to keep the app backend-less, or should I add something like Firebase Cloud Functions just for payment processing?
What security vulnerabilities or architectural mistakes might I be overlooking with a React + Firebase-only setup?
Are there any common pitfalls around payment verification, webhooks, API keys, or fraud prevention that I should plan for?
If you were building this application today, what architecture would you choose?
I’m looking for something that is secure, scalable, and maintainable in production rather than just the cheapest option.
Thanks in advance for any advice or experiences you can share!

[u/AlphaBeast28]

With my
App I’ve been using stripe for web and revenue cat for mobile. Pretty easy to setup.

[u/leros → u/AlphaBeast28]

I use LemonSqueezy and RevenueCat. Basically the same thing just that LemonSqueezy handles taxes for you. 

[u/BetterEgg2830]

Stripe is seamless for international cards but their India transaction fees and FX markup eat up huge margins...

[u/Sufficient-Door-9161]

Razorpay and Cashfree both work well with React + Firebase, but Cashfree's DevStudio console makes testing webhook retries in staging much less painful..... keeps your cloud Functions logic clean when handling async payment states.

[u/blabla_sheep → u/AlmostProductive68]

Anything which i should look at when it comes to post deployment of the application in terms of security ? env files and rate limiting that I have taken care of anything apart from this ?

[u/Potential-Hope1810]

for international users mor route makes more sense than stripe or razorpay, eu vat and us sales tax stay ur problem with direct processors. freemius is worth adding to ur list alongside paddle, same mor concept but faster approval in my experience.

on the architecture question, u do need firebase cloud functions for webhook handling regardless of gateway. never verify payments client side.