A junior developer building simple sites or fixing bugs on someone else's codebase typically sits in the $15–25/hr range while building a portfolio. Mid-level developers who can own a feature end-to-end land closer to the $30–45/hr median. Senior developers with a specialization, security, performance, a specific framework in high demand, routinely charge $75–150/hr, especially for short, high-stakes engagements like a security audit or a performance fix a client needs fast.
A rate only matters if it actually gets collected. Once you've picked a number, send a professional invoice that states your terms clearly, and consider a simple contract for anything beyond a quick one-off, it's the easiest way to avoid scope creep eating into that hourly number. If you want to see how your rate translates into real take-home pay after taxes and time off, try the freelance take-home pay calculator.