It is generally not recommended to eat chicken that has passed its sell-by date. The sell-by date is the date by which stores and suppliers suggest selling the chicken, and after this date, the quality of the chicken may decrease, increasing the risk of foodborne illness.

It is essential to understand that the sell-by date is not the same as the expiration date. The expiration date is the date by which the chicken should be consumed for safety and quality reasons. If chicken is stored correctly, it may still be safe to eat even after its sell-by date, but this depends on several factors.
The quality of the chicken when it was bought is one of the most critical factors. If the chicken was fresh and stored correctly before its sell-by date, it may still be safe to eat several days later. However, if the chicken was already near its sell-by date at the time of purchase, it may not be safe to consume even before the sell-by date has passed.
Another crucial factor is how the chicken was stored. To slow down the growth of bacteria that can cause foodborne illness, chicken should be stored in the refrigerator at a temperature below 40°F (4°C). If the chicken has been stored at a higher temperature, such as in a warmer part of the refrigerator or at room temperature, the risk of bacterial growth increases.
If the chicken has been frozen, it can be safely stored for longer periods. However, safe thawing practices should be followed to avoid contamination. Chicken should be thawed in the refrigerator, in cold water, or in the microwave. Thawing chicken at room temperature should be avoided as it can allow bacteria to grow.
If you decide to eat chicken that has passed its sell-by date, there are steps you can take to reduce the risk of foodborne illness. First, check for any signs of spoilage, such as a foul odor, slimy texture, or discoloration. If the chicken appears to be spoiled, do not consume it.
If the chicken appears to be in good condition, cook it thoroughly to kill any bacteria that may be present. Chicken should be cooked to an internal temperature of at least 165°F (74°C). A meat thermometer can be used to ensure that the chicken has reached this temperature throughout.
Lastly, it is important to handle chicken safely to prevent cross-contamination. This means washing your hands and any surfaces that come into contact with raw chicken, such as cutting boards and utensils, with hot, soapy water. Never place cooked chicken on a plate that previously held raw chicken, and do not reuse marinades or sauces that have come into contact with raw chicken.
In conclusion, while it is not recommended to eat chicken that has passed its sell-by date, it may still be safe to do so under certain conditions. The quality of the chicken at the time of purchase, how it has been stored, and whether it has been thawed correctly all play a role in determining whether it is safe to eat. If you do decide to eat chicken that has passed its sell-by date, it is crucial to check for signs of spoilage, cook it thoroughly, and handle it safely to prevent cross-contamination.