Judge it by criteria, not by mood
Timing a job change based on a passing frustration or a bad week tends to lead to regret. Setting up front, objective markers -- growth stagnation, market conditions, and personal circumstances -- and checking against them gives you a steadier basis for the decision.
Once you have decided on timing, plan the full process
Deciding when to move is only the first step. Once your timing is set, it helps to walk through the broader process of updating your resume, searching discreetly, and negotiating an offer so you are ready to execute once the right opportunity appears.
Frequently Asked Questions
Is there an ideal number of years before changing jobs?
There is no fixed answer, but having spent at least one to two years at a company building a track record of solid results generally makes you a stronger candidate in your next move than leaving too early.
Is it fine to leave immediately if I am unhappy with my current job?
Rather than deciding based on short-term frustration alone, it is worth first figuring out whether the issue is a structural problem or a temporary situation, and deciding carefully from there.