The Nokia Lumia 520 is an affordable handset running Windows Phone 8. Thanks to a dual-core 1GHz processor, the interface is fairly smooth and the phone runs much faster than its predecessors, the Lumia 510 and 610 (both of which had single-core 800 MHz processors). Also, the RAM is doubled from a measly 256MB to a reasonable 512MB. Thus, apps like WhatsApp that were honestly unusable on the prior models works fairly well on the Lumia 520. Next improvement is the addition of a microSD card slot. The phone's back panel comes in bright youthful colours and is user exchangeable, thereby allowing you to change the look of your phone. There's a 5 megapixel autofocus camera at the back, that unfortunately doesn't have an LED flash. There's no front-facing videocall camera; that's a feature available in a version above — the Lumia 620. The most remarkable feature we thought in the phone was PhotoBeamer, which allows you to share photos with any web browser and even lets you control the slideshow from your phone itself! It comes with a 1420 mAh battery.
Nokia Lumia 525 is the successor of the Lumia 520, which became popular due to its attractive Rs. 10k price point. Powered by Windows Phone 8, it’s got a 1GHz Dual-core Qualcomm Snapdragon processor. The Nokia Lumia 520, which was shipped in with only 512MB RAM, resulted in some of the apps being incompatible with the phone. This problem has been fixed as Nokia Lumia 525 offers 1GB RAM. Other than this; the Lumia 525 is practically the same as the Lumia 520. Internal memory of 8GB can be expanded up to 64GB by using a microSD card. It has a 4 inch IPS LCD capacitive touchscreen with 800x480 pixel resolution. In the camera department, it has 5MP rear facing camera with auto focus feature. The only disappointment is that it still lacks a front facing camera and LED flash which are available in other brands in the same price range. Nokia has provided a Radio in Lumia 525. It has an average 1430 mAh battery. So, all in all, not a big difference from the Lumia 520, but more like a marginal upgrade.