Coding agents are AI tools that don't just autocomplete a line — they read your whole repo, plan a multi-step change, write the code, run it, and fix what breaks. Where a normal assistant answers a question, an agent finishes a task.
What makes something an "agent" and not just autocomplete
Three things separate an agent from a smarter autocomplete: it can see context across multiple files instead of just the one you're editing, it can take actions (running commands, editing files, checking output) rather than only suggesting text, and it can loop — try something, see if it worked, and adjust — without you babysitting every step.
How they actually help day to day
The honest use cases are less glamorous than the demos. Agents are good at the boring-but-correct work: migrating a config format across a codebase, writing the test suite for a function you already wrote, tracking down why a build is failing, or doing a first-pass refactor you'll still review line by line.
They're worse at judgment calls — deciding what a feature should actually do, weighing a tradeoff the user cares about, or knowing when "technically working" isn't the same as "right." That part stays on you.
The five worth paying for
We're not ranking them by hype. The five below earned a spot because they save real time on real work, not because they're the loudest in a launch thread. If you're choosing one, start with whichever fits the editor and workflow you already use — switching cost is real, and the gap between the top agents is smaller than the marketing suggests.