Main
Model
Price
Advantages
launch
Announced
Body type
Camera subcategory
Sensor
Effective pixels
Max resolution
Sensor size
Sensor type
Processor
Image ratio w:h
Other resolutions
Sensor photo detectors
Image
ISO
White balance presets
Custom white balance
Image stabilization
Uncompressed format
JPEG quality levels
Boosted ISO (minimum)
Boosted ISO (maximum)
Image stabilization notes
Photography features
Minimum shutter speed
Maximum shutter speed
Aperture priority
Shutter priority
Manual exposure mode
Subject / scene modes
Built-in flash
Flash range
External flash
Flash modes
Continuous drive
Self-timer
Metering modes
Exposure compensation
WB Bracketing
AE Bracketing
Screen / viewfinder
Articulated LCD
Screen size
Screen dots
Touch screen
Screen type
Live view
Viewfinder type
Viewfinder coverage
Viewfinder magnification
Videography features
Resolutions
File Format
Microphone
Speaker
Videography notes
Optics & Focus
Autofocus
Digital zoom
Manual focus
Number of focus points
Lens mount
Focal length multiplier
Physical
Weight (inc. batteries)
Dimensions
Environmentally sealed
Battery
Battery details
Battery Life (CIPA)
Storage
Storage types
Connectivity
USB
HDMI
Microphone port
Headphone port
Wireless
Wireless notes
Remote control
Other features
Orientation sensor
Timelapse recording
GPS
GPS notes
Samples
Videos
Summary
The D3400 highest resolution of 6000 x 4000 pixels (24 megapixels) is better than the D7500 maximum resolution of 5568 x 3712 pixels (21 megapixels). The D7500 offers more focus points in compare with the D3400: 51 vs 11. More number of focus points means more convenience while attempting to focus on subjects that are not centred.
The D7500 has Yes inch touch screen that is bigger than No inch display of the D3400
The D3400 battery life is better than the D7500 battery life. In accordance with CIPA standards the camera owner will be able to produce 1200 shots with the D3400 and only 950 with the D7500. The Nikon D3400 weighs 395g which is 245g lighter than the weight of the D7500. The D7500 can utilize optional accessory GPS devices. This feature can be convenient if you like to travel, to be able to go into the photo metadata and find out exactly where a picture was taken.
Considering the above differences the D7500 will be the best buy. Get the list of the best offers on Amazon.