Businesses often find themselves selling to international customers from around the world. To provide the best user experience, prices on ecommerce sites and other online platforms should display in the local currency of each visitor. But how should you implement currency conversion on your website – client-side or server-side? Both approaches have their merits and downsides regarding accuracy, reliability, ease of integration, and resource requirements.
Defining Client vs Server-Side Conversion
First, what exactly is client vs server-side conversion?
Client-side conversion relies on JavaScript code running locally on the user’s device to detect their location, fetch live exchange rates from a currency converter API, and convert prices dynamically on the frontend. The currency switch happens entirely browser-side without needing to call the backend.
However, server-side conversion constructs the currency functionality as part of the backend application logic. After a user loads a page, the server gets the user’s IP address, queries currency rates, calculates localized prices, and renders the whole page with converted amounts in the user’s native currency.
Accuracy and Reliability
Accuracy and reliability should be the priority when choosing between client-side and server-side conversion. The little inconsistencies or errors in displayed prices can erode customer trust and decrease the cart abandonment rate.
In general, server-side conversion has a higher accuracy and robustness. This allows you to handle all currency calculations on the backend, and you have full control to implement logic that pulls in the most reliable exchange data and applies formatting rules for a given currency. This also makes server-side code immune to tech-savvy visitors who try to alter conversion rates in the browser.
Client-side conversion can also be very accurate if done properly. The trick is to use a trusted currency API like Fixer or CurrencyLayer that offers the latest exchange info back to central bank sources. You will also need to handle edge cases gracefully, such as gracefully falling back to the base currency in case of fetch requests failing.
With rigorous testing and monitoring, you can build client-side currency reliability on par with server-side systems. The extra effort pays dividends in faster page load speeds.
Integration Effort and Code Maintenance
The two approaches vary significantly in ease of integration and the amount of maintenance workload. With client-side conversion, you are calling third-party APIs, which will do the whole currency calculation process for you through a simple JavaScript interface. In most cases if you are popular with your frameworks: React or Angular, you’ll find that there are wrapper libraries available to work with the majority of currency APIs.
By contrast, building homegrown server-side currency logic requires more upfront development effort. The server app needs to independently handle IP geolocation, live rate fetching, localized formatting, and storage of exchange data. However, an advantage is that centralized server-side code is easier to monitor and maintain down the road. Changing conversion business logic only requires updating application code rather than assets loaded on the client.
Resource Usage and Performance
Client-side and server-side conversion also differ in their infrastructure resource requirements and impacts on page performance:
- Client-side conversion offloads the currency conversion workload entirely to the user’s browser. This reduces the load on the server infrastructure. Running JavaScript code on the client still means there’s a lag or jank if the performance is poor.
- The currency localization is handled on the backend in server-side conversion. It puts a huge load on server resources at peak time, but avoids slow page load from client-side JavaScript.
- With caching, compression, and edge location routing, CDNs can optimize the delivery server server-rendered pages. However, the hosting cost may increase with additional infrastructure to absorb currency computation workloads.
In general, client-side conversion is preferable for consumer-facing websites with unpredictable traffic spikes. Server-side conversion makes sense for controlled traffic volumes where the backend infrastructure can be precisely provisioned.
Use Case Examples
The way of dealing with currency localization across different platforms boils down to how wide or specific the intended audience and scale of the platform are. Below are two different examples of how businesses adapt the implementation to match what they need.
Global Ecommerce Site
For a high-traffic ecommerce store with customers worldwide, Shopify relies on client-side conversion to localize currencies across its platform. JavaScript detects the user’s location, fetches Open Exchange Rates API data for currency formatting details and current rates, then inserts converted values for all product pricing onsite. This front-end conversion prevents Shopify’s servers from having to handle currency localization requests for every page view. Offloading the work to browsers scales easily without provisioning infrastructure for peak loads.
Domestic News Site
The Guardian is a UK-focused online newspaper with British readers and uses server-side conversion in the form of GeoPlugin. For visitors who geolocate to their backend stacks, they handle presenting prices for paid content subscriptions or article passes in pounds sterling for domestic users. By relying on centralized servers, rather than distributed client devices, developers of their currency have more control over currency accuracy for the mostly homogeneous reader base.
Global Game Studio
For their gaming titles, Angry Birds creators Rovio Entertainment localizes in-app purchases for 30 currencies. On the one hand, they’re client and server side, integrating the best performance and control qualities: a lightweight JavaScript snippet gets rates and does conversions as needed, while our backend servers run periodically to pre-generate currency data to serve a client app. It splits responsibilities for converting globally and performing millions of price calculations per day.
Key Decision Factors
When weighing client vs server-side conversion, consider these key decision points:
- Traffic Volume. Client-side scales better for heavy traffic.
- Infrastructure Costs. Server-side requires more currency compute capacity.
- Audience Location. More homogeneity favors server-side.
- Page Speed Importance. Client optimization is faster for browsers.
- Conversion Criticality. The server offers more control for pricing accuracy.
By balancing these factors against business goals and technical constraints, you can determine the best currency conversion architecture.
Often, a hybrid approach proves optimal – for instance, client handling routine traffic with server-side processes pregenerating currency data to seed the frontend and handle exceptions.
Conclusion
Both client-side and server-side currency conversion offer workable solutions to localizing prices for global customers. Client-side conversion places currency processing on the user’s browser for faster page loads, easier scalability, and reduced server workload at the cost of relying on external APIs. Server-side conversion builds currency logic directly into backend application code for stricter accuracy guarantees and centralized control, but incurs higher infrastructure expenses.
Carefully evaluate your business and technical environment when deciding between approaches. GeoPlugin and other geolocation tools provide versatile multi-format APIs that allow currency conversion partitioning across client and server for hybrid implementations able to balance conversion accuracy, speed, and reliability. With mindful architecture decisions, you can deliver robust, scalable, and high-performance currency experiences tailored to your unique needs.
