Claude Code vs OpenCode vs Cline vs Aider: Which AI Coding Agent Should You Use?

Four tools. One terminal. A pile of strong opinions.

Claude Code, OpenCode, Cline, and Aider all promise to write your code for you, and they all do it differently enough that the wrong pick will cost you either money or sanity. I have three of these four installed on the machine I'm writing this on: claude 2.1.177, aider 0.86.2, and opencode 1.15.13. Cline is the odd one out, because it isn't a CLI at all. It lives inside your editor. That single fact already tells you most of what you need to know about who each tool is for.

So this isn't a balanced overview. By the end you'll know which one I'd hand a junior dev, which one I'd run on a plane with no wifi, and which one quietly drains a credit card. (AI-assisted: drafted with a model, then checked against the live tools and their docs in June 2026 — version numbers and commands below were run, not guessed.)

Pick wrong and you feel it within a week.

Some of these agents live in your terminal. One lives inside VS Code and refuses to leave. Some let you swap in any model you want, including a free one running on your own GPU. Others lock you to a single vendor and bill by the token. Those aren't cosmetic differences. They decide whether your code ever leaves your laptop, whether you can work offline, and whether a long refactor costs you nothing or forty dollars.

The point of comparing them is to match the tool to how you already work, not to crown a single winner that suits everyone. There isn't one.

I judged all four on five things that actually change day to day:

• Where it runs. Terminal, IDE, or both? A terminal tool drops into any SSH session. An IDE tool gives you syntax highlighting and inline diffs for free.
• Model choice. Can you point it at a local model, a cheap one, and an expensive one, or are you stuck with whatever the vendor ships?
• How much rope it gets. Does the agent run builds and fix its own errors unattended, or does it stop and ask before touching a file?
• What it costs you to run all day. Flat subscription, pay-per-token, or genuinely free on local hardware.
• Where your code goes. Does it ship to a vendor's servers, or can it stay on your machine?

Those five map cleanly onto real jobs: fixing a bug, shipping a feature, untangling a stack trace. Keep them in mind. The verdict at the end leans on every one of them.

Claude Code is the one I reach for when I want the agent to just handle it.

Anthropic built it, it runs in your terminal, and on this machine it reports version 2.1.177 (Claude Code). What sets it apart is how little babysitting it needs. Hand it a messy task and it plans the steps, runs the build, reads the error output, and tries again without asking you to approve each move.

Where it's strong:

• Planning. It splits a vague request into ordered steps and works through them with almost no prompting.
• Big context. A large context window lets it hold a sprawling codebase in mind, so it doesn't lose track of how files depend on each other.
• Runs things itself. It executes builds, reads the failures, and iterates. You watch.
• Connects to your stack. Through the Model Context Protocol (MCP) it talks to databases, browsers, APIs, and tools you wire up yourself.
• Remembers. It picks up your project's patterns over a session and stops re-asking the same questions.

Where it bites:

• Rate limits. Even on a Max plan you can hit a wall mid-flow and have to wait it out.
• Closed source. Your code goes to Anthropic's servers. For a regulated or secret codebase, that's a real problem, not a footnote.
• One model, take it or leave it. It runs Claude models only. No GPT, no local Qwen, no switching to something cheaper for the boring parts.
• Token bills add up. On the pay-per-token API, a few intensive sessions get expensive fast.

The pricing is refreshingly simple, and I confirmed these tiers against Anthropic's 2026 plans before writing them down.

| Plan | Monthly cost | What you get |

|------|-------------|----------|

| Pro | $20/month | Claude Code in terminal, web, and desktop; Sonnet 4.6 and Opus 4.6; enough budget for focused sessions |

| Max 5x | $100/month | Five times the Pro usage, for people who keep hitting the ceiling |

| Max 20x | $200/month | Twenty times Pro usage; rate limits basically stop mattering for full days of work |

| API (BYOK) | Pay per token | Sonnet 4.6 starts around $3 per million input tokens, $15 per million output |

If you code most days, the flat subscription wins easily. The API route only makes sense for light or bursty use, or when you want hard cost control per request. Run the math on a heavy week and the $200 tier often comes out cheaper than the same work billed by the token.

OpenCode is the answer when "my code goes to a vendor's server" is a dealbreaker.

It's an open-source terminal agent, now maintained under the anomalyco/opencode repo, which sits north of 170,000 GitHub stars as of June 2026 and ships releases almost daily (the latest tagged build was v1.17.4 on June 12, 2026). The version on my machine is 1.15.13, a couple of releases behind the tip, which tells you how fast it moves. The npm package, worth noting because the obvious name is wrong, is opencode-ai. Plain opencode on npm is a 404.

What makes it worth the setup:

• Any model you want. Local models through Ollama, or cloud APIs from Anthropic, OpenAI, and others. Switch per task.
• Code can stay home. Point it at a local model and nothing leaves your machine. No vendor sees your source.
• Plugins and themes. A real community ecosystem of extensions, not just a config file.
• Moves fast. Daily releases and a large contributor base mean bugs get fixed and models get supported quickly.

The honest tradeoff: running it fully local with Ollama costs you zero per-token dollars, but you pay in setup and in raw model quality. A 32B model on your own GPU is good. It is not Opus 4.6. Claude Code is more polished out of the box. OpenCode is the one you tinker with.

Here's the install that actually works. The package name trips people up, so use this exactly:

# Install globally from npm (note: the package is opencode-ai, not opencode)
npm install -g opencode-ai@latest

# Or use the official installer script
curl -fsSL https://opencode.ai/install | bash

# Then just run it in your project
opencode

Going fully local with Ollama (zero per-token cost, nothing leaves your machine):

# Install Ollama
curl -fsSL https://ollama.com/install.sh | sh

# Pull a capable coding model
ollama pull qwen3:32b

# OpenCode detects local Ollama models automatically
opencode

OpenCode itself is free. Your bill, if any, comes entirely from the model provider you point it at.

| Provider | Cost | Best for |

|----------|------|----------|

| Local (Ollama) | $0, plus electricity | Privacy, offline work, never paying per token |

| Anthropic API | roughly $3-75/M tokens | Top-tier Claude quality without the subscription |

| OpenAI API | roughly $2.50-60/M tokens | GPT models when you want a second opinion |

One gotcha I'd flag: if you installed an old opencode build before, remove it first. The docs explicitly warn that pre-0.1.x versions conflict with the current package.

Cline never touches a file without your say-so. That's the whole pitch.

It's an open-source (Apache 2.0) extension that lives inside your editor, with more than 5 million installs and around 61,000 GitHub stars by 2026. Every change it proposes waits for you to approve it. Where Claude Code charges ahead, Cline stops and shows you the diff first.

Why people swear by it:

• You approve everything. Nothing gets written or run until you click yes. That's a safety net for production code.
• Plan and Act modes. Its signature feature: use a heavy reasoning model to plan, then a cheaper, faster model to execute. Plan mode can only read and propose. It can't change a thing.
• Pick your model. Its provider list crossed 30 in 2026, including Anthropic, OpenAI, Gemini, DeepSeek, xAI Grok, and local models.
• Costs on screen. It shows the running cost of each request as you go, so no surprise bill.
• Drives a browser. It can launch a headless browser to test and debug visual bugs.

Where it grates:

• Editor-bound. It started as VS Code only. By 2026 it reached JetBrains, Cursor, Windsurf, Zed, and Neovim, plus a preview CLI for Mac and Linux, but it's still built around an editor, not a bare terminal.
• Approval fatigue. On a big refactor, clicking approve a hundred times gets old.
• It can lag. On large projects the extension can drag VS Code down.
• Less autonomy by design. That's the point, but if you want fire-and-forget, this isn't it.

Reach for Cline in two situations specifically:

1. Touching code that's live. When a bad edit means a production incident, the approve-every-change model earns its keep. You see the diff before it lands.
2. Learning or teaching. Plan mode spells out what it intends to do and why before it does anything. That running commentary is genuinely useful when you're still building intuition, or when you're walking someone else through a change.

If neither of those is you, the constant approvals will feel like a tax. Pick a more autonomous tool.

Aider treats Git as a first-class citizen, and that's its whole personality.

It runs in your terminal, and every change it makes becomes a real Git commit with a sensible message. That means you can undo any edit the normal way, with git diff and git revert, instead of trusting a proprietary undo button. On this machine it reports aider 0.86.2, installed through pipx (~/.local/share/pipx/venvs/aider-chat), which is the standard way in.

What it does better than the rest:

• Git-native. Auto-commits with clear messages. Your history stays clean and reversible.
• Terminal-first. No editor required. It drops into any shell, including a remote one.
• Architect mode. Run --architect and it uses one model to plan the edit and another to write it, which lands tricky changes more reliably (I confirmed the flag exists in aider --help).
• Highly configurable. You can point it at almost any model with --model and --api-key PROVIDER=KEY, and tune the edit format to taste.

The catch:

• You need Git fluency. If git rebase makes you nervous, Aider's strengths are wasted on you.
• No real IDE story. It's terminal through and through. No inline diffs in your editor.
• Smaller crowd. Fewer tutorials and Stack Overflow answers than the big commercial tools.

Here's the part the old version of this guide got wrong, so I checked it directly. There is no aider init, no aider connect, and no aider pair. Those commands don't exist. The real flow is short:

# Recommended install (sets up an isolated env via uv)
python -m pip install aider-install && aider-install

# Or, simpler, with pipx (how it's installed on the machine I tested)
pipx install aider-chat

# macOS Homebrew also works
brew install aider

# Then cd into a git repo and start, naming a model + key
cd your-project
aider --model sonnet --api-key anthropic=sk-...

Aider finds your Git repo on its own. You don't initialize anything. Once it's running, you just describe the change in plain English and it edits the files and commits the result.

Aider is free. Your only cost is the model provider's API, and because you can point --model at a cheap or local model, you control that bill directly.

So which one? Here's where I land after running three of the four and reading the docs on all of them.

Want it to just work, and you'll pay for that? Claude Code. It's the most autonomous and the most polished, and the flat $20-$200 plans are honest. Skip it if your code can't legally leave your network, or if model lock-in bothers you. Care about privacy, or want a $0 bill? OpenCode. Run a local model through Ollama and nothing leaves your laptop and nothing hits a credit card. Just budget an evening for setup, and remember the package is opencode-ai. Touching production, or teaching someone? Cline. The approve-every-change model and Plan mode are exactly what you want when a mistake is expensive or when the commentary is the point. Skip it if approval clicks will drive you up the wall. Live in the terminal and trust Git? Aider. Every edit is a clean, reversible commit, and you control the model and the cost. Skip it if Git makes you nervous or you want an IDE experience.

My honest default for most working developers: start with Claude Code if budget allows, and keep OpenCode + Ollama in your back pocket for the offline day and the sensitive repo. Those two cover almost everything between them.