---
title: "Cheapest Coding Agent in 2026: Free and Low-Cost Options | Reason Machines"
description: "The cheapest coding agent in 2026, from each vendor's pricing page: free open-source agents (opencode, Aider, Cline, Kilo Code), $0 plans (Codex in ChatGPT Free, Copilot Free, Antigravity, Devin, Jules), and paid plans from $8 a month."
url: "https://reasonmachines.com/guides/cheapest-coding-agent"
section: "Coding agent guides"
---

# Cheapest coding agent in 2026: free and low-cost options

The cheapest coding agents cost nothing up front: opencode, Aider, Cline and Kilo Code are free and open source, so you pay only your model provider (or nothing with a local model), and Codex in ChatGPT Free, GitHub Copilot Free, Google Antigravity, Devin and Jules all have $0 plans with tight limits. The cheapest paid plans are ChatGPT Go and Cursor Plus at $8 a month and Copilot Pro at $10, and if you already pay for AI subscriptions, an agent that runs on the ones you have avoids paying twice.

Updated Nov 2026

[Start with Reason](https://reasonmachines.com/) on the web, or [download Reason for macOS](https://reasonmachines.com/download).

## Use the subscriptions you already pay for in Reason

1. **Open Reason on the web or the Mac app**: Sign in at reasonmachines.com, or download the Reason app for macOS from reasonmachines.com/download. Both open the same Sessions. Sending work to Reason needs a Pro or Max plan.
2. **Connect the plans you already pay for**: In Settings › Models, under Subscriptions, connect ChatGPT (Plus, Pro or Business), Claude (Pro or Max), Grok (SuperGrok or X Premium+) or GitHub Copilot, and add API keys if you have them. Work on those accounts is billed by their provider, not in Reason credits.
3. **Pick the model per task**: In the composer, choose the model for each Session: a smaller model for routine fixes, a larger one for hard changes. Each Session shows the model and account it ran on.
4. **Keep going at a limit**: When the account a turn runs on hits its limit, Reason moves the turn to your other connected accounts for that provider, then to Reason credits if your workspace can pay, and says so in the conversation.

## Coding agents by price

| Agent | Free option | Lowest paid price | What to know |
| --- | --- | --- | --- |
| opencode | Free, MIT; free models for a limited time | OpenCode Go $10 a month | 75+ providers and local models; Go has five-hour, weekly and monthly dollar limits |
| Aider | Free, Apache-2.0 | None; you pay your model provider | Terminal pair programming with almost any LLM, local ones included |
| Cline | Free for individual developers | None; you pay for inference | Bring your own key, or local models through Ollama and LM Studio |
| Kilo Code | Free and open source | Teams $15 per user; Kilo Pass $19 a month | Gateway at provider rates; usage billed separately |
| Codex | ChatGPT Free, desktop app, subject to rollout | ChatGPT Go $8; Plus $20 a month | Plus adds the CLI, IDE extension, web and iOS |
| GitHub Copilot | Free: 2,000 completions a month, auto model only | Pro $10 a month | All plans include Copilot CLI |
| Google Antigravity | $0 a month with basic weekly rate limits | Google AI Pro | Google's agentic coding app |
| Cursor | Free: limited agent requests | Plus $8 a month, Grok models only | Other vendors' models are billed separately |
| Devin | Free: light quota, limited models | Pro $20 a month | Allowances refresh daily and weekly |
| Jules | 15 tasks a day free | Google AI Pro | Paid plans for personal Google accounts |
| Claude Code | None | Claude Pro $20 a month ($17 billed annually) | Or API billing; Anthropic says about $13 per developer per active day on average |

From each vendor's pricing page, docs or license, checked Nov 2, 2026; US list prices.

## Free isn't free once you count the model

Open-source agents are free to run, but the model isn't: you pay your provider per token, or run a local model, which costs nothing per token but limits quality to what your hardware can run. $0 plans from Codex, Copilot, Antigravity, Devin and Jules are real but small, and meant for trying the product.

What a task really costs depends on the model, how many tokens the agent spends, and whether it finishes. Compare agents on the same task, on your own repository, rather than on list price alone.

- [Cheaper alternative to Claude Code](https://reasonmachines.com/guides/cheaper-claude-code-alternative.md)
- [Cheapest way to use Claude Code](https://reasonmachines.com/guides/cheapest-way-to-use-claude-code.md)
- [Best coding agents in 2026](https://reasonmachines.com/guides/best-coding-agents.md)
- [Claude Code alternatives, free ones included](https://reasonmachines.com/guides/claude-code-alternatives.md)

## Reason: all your AI subscriptions in one coding agent

Use the subscriptions you already pay for (ChatGPT Plus/Pro/Business, Claude Pro/Max, SuperGrok or X Premium+, GitHub Copilot) or your own API keys in one coding agent. Hit your limit? Reason keeps going on your other connected accounts or Reason credits.

Reason isn't the lowest-priced agent on this page: Pro is $50 a month with 1,250 credits a week, and Max is $200 with 5,000; a credit is $0.04. Work on your own connected subscriptions or API keys is billed by that provider, not in Reason credits, so you don't pay twice for a plan you already have.

On cost: in Reason's published benchmark on GPT-6 Astra at xhigh effort, with the same tasks and graders, Reason 1.1 scored 65.1 against Codex's 62.5 on Coding Agent Index v1.5, at 22% lower cost per solved task. That's Reason's benchmark of its own harness, with the runner published to reproduce it.

- [Use all your AI subscriptions in one coding agent](https://reasonmachines.com/guides/use-all-your-ai-subscriptions.md)
- [Reason vs Codex: the benchmark](https://reasonmachines.com/guides/reason-vs-codex.md)
- [Claude Max alternative](https://reasonmachines.com/guides/claude-max-alternative.md)

## Sources (checked Nov 2, 2026)

- [anomalyco/opencode on GitHub (MIT)](https://github.com/anomalyco/opencode)
- [opencode docs: OpenCode Go](https://opencode.ai/docs/go)
- [Aider-AI/aider on GitHub (Apache-2.0)](https://github.com/Aider-AI/aider)
- [Cline: pricing](https://cline.bot/pricing)
- [Kilo Code: pricing](https://kilo.ai/pricing)
- [OpenAI: Codex pricing](https://developers.openai.com/codex/pricing)
- [GitHub Docs: Copilot plans](https://docs.github.com/en/copilot/get-started/plans)
- [Google Antigravity: pricing](https://antigravity.google/pricing)
- [Cursor: pricing](https://cursor.com/pricing)
- [Devin: pricing](https://devin.ai/pricing)
- [Jules docs: usage limits](https://jules.google/docs/usage-limits)
- [Anthropic: Claude plans and pricing](https://claude.com/pricing)
- [Claude Code docs: manage costs effectively](https://code.claude.com/docs/en/costs)
- [Reason: Reason 1.1 Coding Agent Index results (Oct 10, 2026)](https://reasonmachines.com/blog/introducing-reason-agent-1-1.md)
- [Reason docs: plans](https://docs.reasonmachines.com/docs/plans)

## Questions

### What is the cheapest coding agent?

The free, open-source ones: opencode, Aider, Cline and Kilo Code cost nothing to use, and you pay only your model provider, or nothing with a local model. Among hosted plans, Codex in ChatGPT Free, Copilot Free, Antigravity, Devin and Jules have $0 tiers.

### Is there a free coding agent?

Yes. opencode (MIT), Aider (Apache-2.0) and Cline are free and open source, and Codex, Copilot, Antigravity, Devin and Jules have free plans with small limits.

### Are bring-your-own-key agents really free?

The agent is; the model isn't. You pay your provider per token, or run a local model, which is free per token but depends on your hardware.

### What is the cheapest paid coding plan?

ChatGPT Go and Cursor Plus are $8 a month (Go runs Codex in the desktop app; Cursor Plus is Grok models only), GitHub Copilot Pro is $10, and OpenCode Go is $10.

### Is Claude Code free?

No. It comes with Claude Pro at $20 a month ($17 billed annually) and higher plans, or bills the API by token.

### Is Reason the cheapest coding agent?

No. Reason's plans start at $50 a month. It saves money when you already pay for AI subscriptions, because it runs on them instead of charging for that usage again, and in its own benchmark it cost 22% less per solved task than Codex on the same model.

## More guides

- [Claude Code alternatives, free ones included](https://reasonmachines.com/guides/claude-code-alternatives.md)
- [Reason vs Codex](https://reasonmachines.com/guides/reason-vs-codex.md)
- [Best coding agents in 2026](https://reasonmachines.com/guides/best-coding-agents.md)
- [Use all your AI subscriptions in one coding agent](https://reasonmachines.com/guides/use-all-your-ai-subscriptions.md)
- [Cheaper alternative to Claude Code](https://reasonmachines.com/guides/cheaper-claude-code-alternative.md)
- [Claude Max alternative](https://reasonmachines.com/guides/claude-max-alternative.md)
- [All coding agent guides](https://reasonmachines.com/guides.md)
- [Download Reason for macOS](https://reasonmachines.com/download)