| { |
| "title": "Claude Code vs Codex: startup tokens, MCP tools and the same coding task", |
| "url": "https://tokensave.app/data/claude-code-vs-codex-tokens", |
| "license": "CC BY 4.0", |
| "measured": "2026-10-18 and 2026-10-22", |
| "citation": "TokenSave (2026). Claude Code vs Codex: startup tokens, MCP tools and the same coding task [Data set]. Zenodo. https://doi.org/10.5281/zenodo.23448342", |
| "startup": { |
| "prompt": "Reply with the single word OK.", |
| "mcp_server": "Self-written stdio MCP server (mcp_dummy.js) exposing N tracker tools, each with a one-sentence description and a 5-property input schema. Full definitions: 151 o200k tokens per tool, 4,541 for 30 tools.", |
| "full_definition_tokens_o200k": { |
| "1": 151, |
| "30": 4541 |
| }, |
| "codex_tool_use_check": { |
| "mcp_tools": 10, |
| "input_tokens": 47876 |
| }, |
| "rows": [ |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5 (default, Max plan)", |
| "mcp_tools": 0, |
| "run1": 35765, |
| "run2": 35777, |
| "avg": 35776, |
| "added_vs_no_mcp": 0, |
| "runs": [ |
| 35765, |
| 35777, |
| 35781, |
| 35781 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5 (default, Max plan)", |
| "mcp_tools": 1, |
| "run1": 35790, |
| "run2": 35790, |
| "avg": 35792, |
| "added_vs_no_mcp": 16, |
| "runs": [ |
| 35790, |
| 35790, |
| 35794, |
| 35794 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5 (default, Max plan)", |
| "mcp_tools": 10, |
| "run1": 35913, |
| "run2": 35913, |
| "avg": 35915, |
| "added_vs_no_mcp": 139, |
| "runs": [ |
| 35913, |
| 35913, |
| 35917, |
| 35917 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5 (default, Max plan)", |
| "mcp_tools": 30, |
| "run1": 36165, |
| "run2": 36165, |
| "avg": 36167, |
| "added_vs_no_mcp": 391, |
| "runs": [ |
| 36165, |
| 36165, |
| 36169, |
| 36169 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort low (ChatGPT plan)", |
| "mcp_tools": 0, |
| "run1": 14678, |
| "run2": 14678, |
| "avg": 14748, |
| "added_vs_no_mcp": 0, |
| "runs": [ |
| 14678, |
| 14678, |
| 15018, |
| 14618 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort low (ChatGPT plan)", |
| "mcp_tools": 1, |
| "run1": 14678, |
| "run2": 14678, |
| "avg": 14648, |
| "added_vs_no_mcp": -100, |
| "runs": [ |
| 14678, |
| 14678, |
| 14618, |
| 14618 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort low (ChatGPT plan)", |
| "mcp_tools": 10, |
| "run1": 14678, |
| "run2": 14678, |
| "avg": 14648, |
| "added_vs_no_mcp": -100, |
| "runs": [ |
| 14678, |
| 14678, |
| 14618, |
| 14618 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort low (ChatGPT plan)", |
| "mcp_tools": 30, |
| "run1": 14678, |
| "run2": 14678, |
| "avg": 14648, |
| "added_vs_no_mcp": -100, |
| "runs": [ |
| 14678, |
| 14678, |
| 14618, |
| 14618 |
| ], |
| "run_dates": [ |
| "2026-10-18", |
| "2026-10-18", |
| "2026-10-22", |
| "2026-10-22" |
| ] |
| } |
| ] |
| }, |
| "same_task": { |
| "measured": "2026-10-18 (runs 1-2) and 2026-10-22 (runs 3-5)", |
| "prompt": "Make a brick-breaker game that runs in the browser as a single file named index.html in the current folder. It needs 2 levels, a score display and 3 lives, and it must be playable with the keyboard and the mouse. Write the file and finish.", |
| "setup": "Each run in its own empty folder, no MCP servers. Claude Code: claude -p --effort medium --permission-mode acceptEdits --output-format json; tokens from modelUsage, cost is Claude Code list API cost. Codex: codex exec --json -s workspace-write -c model_reasoning_effort=\"medium\"; tokens from turn.completed. Time is wall-clock. Every game loaded without errors and showed 2 levels, score and 3 lives in a headless browser check.", |
| "rows": [ |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5, effort medium", |
| "run": 1, |
| "input_tokens": 123666, |
| "cached_input_tokens": 95504, |
| "output_tokens": 8537, |
| "seconds": 73, |
| "api_cost_usd": 0.42, |
| "file_lines": 487, |
| "file_chars": 14992, |
| "works": true, |
| "measured": "2026-10-18" |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5, effort medium", |
| "run": 2, |
| "input_tokens": 79213, |
| "cached_input_tokens": 51762, |
| "output_tokens": 7870, |
| "seconds": 63, |
| "api_cost_usd": 0.39, |
| "file_lines": 527, |
| "file_chars": 15088, |
| "works": true, |
| "measured": "2026-10-18" |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort medium", |
| "run": 1, |
| "input_tokens": 47954, |
| "cached_input_tokens": 29824, |
| "output_tokens": 2872, |
| "seconds": 33, |
| "api_cost_usd": null, |
| "file_lines": 49, |
| "file_chars": 7566, |
| "works": true, |
| "measured": "2026-10-18" |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort medium", |
| "run": 2, |
| "input_tokens": 48815, |
| "cached_input_tokens": 37504, |
| "output_tokens": 3803, |
| "seconds": 41, |
| "api_cost_usd": null, |
| "file_lines": 117, |
| "file_chars": 10045, |
| "works": true, |
| "measured": "2026-10-18" |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5, effort medium", |
| "run": 3, |
| "input_tokens": 79316, |
| "cached_input_tokens": 51766, |
| "output_tokens": 7897, |
| "seconds": 62, |
| "api_cost_usd": 0.3887, |
| "file_lines": 513, |
| "file_chars": 14756, |
| "works": true, |
| "measured": "2026-10-22" |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5, effort medium", |
| "run": 4, |
| "input_tokens": 77868, |
| "cached_input_tokens": 51766, |
| "output_tokens": 6595, |
| "seconds": 52, |
| "api_cost_usd": 0.3511, |
| "file_lines": 421, |
| "file_chars": 12034, |
| "works": true, |
| "measured": "2026-10-22" |
| }, |
| { |
| "tool": "claude_code", |
| "tool_name": "Claude Code 2.1.295", |
| "model": "claude-opus-5-5, effort medium", |
| "run": 5, |
| "input_tokens": 78830, |
| "cached_input_tokens": 51766, |
| "output_tokens": 7447, |
| "seconds": 60, |
| "api_cost_usd": 0.3758, |
| "file_lines": 420, |
| "file_chars": 13618, |
| "works": true, |
| "measured": "2026-10-22" |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort medium", |
| "run": 3, |
| "input_tokens": 70704, |
| "cached_input_tokens": 60032, |
| "output_tokens": 7118, |
| "seconds": 75, |
| "api_cost_usd": null, |
| "file_lines": 29, |
| "file_chars": 9756, |
| "works": true, |
| "measured": "2026-10-22" |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort medium", |
| "run": 4, |
| "input_tokens": 48362, |
| "cached_input_tokens": 37248, |
| "output_tokens": 3468, |
| "seconds": 72, |
| "api_cost_usd": null, |
| "file_lines": 46, |
| "file_chars": 9368, |
| "works": true, |
| "measured": "2026-10-22" |
| }, |
| { |
| "tool": "codex", |
| "tool_name": "Codex CLI 0.162", |
| "model": "gpt-6-luna, reasoning effort medium", |
| "run": 5, |
| "input_tokens": 47975, |
| "cached_input_tokens": 37248, |
| "output_tokens": 3103, |
| "seconds": 57, |
| "api_cost_usd": null, |
| "file_lines": 51, |
| "file_chars": 8660, |
| "works": true, |
| "measured": "2026-10-22" |
| } |
| ] |
| } |
| } |
