On March 14th, the JR East rail company raised its fare, the first hike since 1987. The increase is higher in central Tokyo and the JR Yamanote Line area, where the fare goes up by 16.4%.
For a single ride, the difference will be several hundred yen at the most so not a huge difference, though commuters that use the rail on a regular basis will feel the impact more.
Shinjuku-Shibuya 167→199 JPY
Tokyo-Shinjuku 208→253 JPY
Tokyo-Yokohama 483→ 528 JPY
Tokyo-Sendai 6,050→6,270 JPY (base fare only)
On certain routes, travelers may want to consider using a competing line that runs a similar section.
For example, the Shinjuku-Hachioji section now costs 616 JPY, up from 492. The Keio Corporation, which also connects these two stations using a more southerly route costs 409 JPY. The JR train has a slight edge in travel time, taking about 35 minutes while a Keio limited express train will take around 40-45 minutes.
The Shinjuku-Takao section also sees competition between these two operators; a ride on the JR Line will now cost 715 JPY whereas the Keio Line is 409 JPY.
Route search sites like NAVITIME or Jorudan have already updated their fare information so the new fare will show up in research. Also confirm that a route search done on Google Maps already reflects the new JR fare.