Open Benchmarks Grants

Terminal-Bench 4.0

A benchmark to measure and evolve with the frontier of agent work: real terminal environments, real software engineering tasks, and a rolling task set that is revised as agents catch up to it. Version 4.0 trims the 3.0 task set from 74 to 66 tasks, removing eight and revising 20.

Built with
Image
Image
Image

Overview

Terminal-Bench measures whether an AI agent can operate a real terminal to complete real software engineering and systems tasks: writing and debugging code, configuring environments, and recovering from failure, all without a GUI. Version 3.0 introduced the current 74 task families; version 4.0 is a maintenance release that removes eight tasks and revises twenty, netting 66 tasks, with no new tasks added in this cycle.

Headline finding, in this evaluation: Claude Opus 5 (Claude Code, max effort) leads at 51.8% ± 3.4% resolution, roughly 7 points ahead of Claude Fable 5 in second place. The bottom of the ranked field, Grok 4.5 and Claude Sonnet 5, both land at 12.4%, a spread of nearly 40 points across the ten evaluated model and agent configurations.

Snorkel AI contributes to Terminal-Bench 4.0 as both a task author and a data partner with additional support via the Open Benchmarks Grants program and Snorkel's Justin Bauer among the benchmark's reviewers.

At a glance

66

tasks in v4.0.0, down from 74 in v3.0.0

8

tasks removed in v4.0.0

20

tasks revised in v4.0.0

Leaderboard

Rank Model Effort Agent Resolution Rate Release Date Tokens Cost
1 Opus 5 max Claude Code
51.8% ±3.4
2026-07-24 6.5B $6.0k
2 Fable 5 max Claude Code
44.5% ±3.8
2026-06-09 3.8B $7.3k
3 GLM-5.3 max Claude Code
41.8% ±3.2
2026-08-14 8.7B $2.7k
4 GPT-5.6 Sol max Codex
37.3% ±3.8
2026-06-26 4.4B $2.5k
5 Opus 4.8 max Claude Code
23.6% ±3.6
2026-05-28 6.4B $6.5k
6 GPT-5.6 Terra max Codex
21.5% ±3.3
2026-06-26 5.7B $1.7k
7 Grok 4.6 high Grok Build
20.3% ±3.1
2026-08-12 4.0B $3.6k
8 GPT-5.6 Luna max Codex
17.3% ±2.8
2026-06-26 11.6B $0.3k
9 Grok 4.5 high Grok Build
12.4% ±2.6
2026-07-16 3.4B $2.1k
10 Sonnet 5 max Claude Code
12.4% ±3.1
2026-06-30 21.6B $9.6k

How Terminal-Bench 4.0 compares

Benchmark

Released

Tasks

Change

Terminal-Bench 4.0

Aug 2026

66

8 tasks removed, 20 revised, 0 added

Terminal-Bench 3.0

Jul 2026

74

New rolling task set (formerly branded Frontier-Bench); initial 74 tasks added

Terminal-Bench 2.1

May 2026

89

Revision fixing 28 tasks; task count unchanged

Terminal-Bench 2.0

Nov 2025

89

Harder, curated task set; introduced Harbor, the agent eval and optimization framework

Terminal-Bench 1.0

May 2025

80

Initial release (Terminal-Bench-Core), led by Stanford and the Laude Institute

Methodology

Resolution rate

Share of the 66 v4.0.0 tasks each agent and model configuration resolves, reported with a margin reflecting run—to—run variance. “Effort” (max, high, and similar) is the harness’s own reasoning or agent effort setting for that run, not a Terminal-Bench parameter.
Cost and tokens
Totals are for the full evaluation run across all 66 tasks, not per task; they are not normalized for effort setting, so runs with a higher effort setting (like Sonnet 5’s) show substantially higher token and cost totals without a proportional gain in resolution rate.
Contamination control

The public Terminal-Bench site marks its task and leaderboard data with a canary string, requesting that benchmark data not appear in model training corpora.

Run command

Evaluated via the Harbor evaluation harness: harbor run -d terminal-bench/terminal-bench@4.0.0. Dataset pinned at hub.harborframework.com.

From the blog

Image for Terminal-Bench 4.0: Why Continuous Benchmarks Require Continuous QA

Terminal-Bench 4.0: Why Continuous Benchmarks Require Continuous QA

The speed of new frontier model releases keeps accelerating. Meanwhile benchmarks struggle to keep up and saturate quickly, often being...
August 28, 2026

Acknowledgments

Terminal-Bench is hosted by Harbor and the Laude Institute, and supported by Snorkel AI via the Open Benchmarks Grants program. The v4.0.0 release was authored by Ryan Marten and Snorkel's Justin Bauer is among the benchmark's senior reviewers. 

FAQs

Get notified when we launch a new benchmark

Share this benchmark

More benchmarks

New
Open Benchmarks Grants

Terminal-Bench-Science

A benchmark for evaluating AI agents on workflows from researchers’ own work. Scientists, not model developers or vendors, set the bar for scientific capability in AI.

By Resolution Rate
1
Image
Claude Opus 5 (Claude Code)
30.0%
2
Image
GPT-5.6 Sol (Codex)
22.4%
3
Image
Claude Fable 5 (Claude Code)
21.4%
Open Benchmarks Grants

Terminal-Bench 3.0

The next frontier benchmark for agent work. A harder, more domain-diverse successor to Terminal-Bench 2.1 — built in the open, task by task, under continuous adversarial review.

By Resolution Rate
1
Image
Opus 5 (max) • mini-SWE-agent
42.7%
2
Image
GPT-5.6 Sol (max) • Codex
34.6%
3
Image
Fable 5 (max) • Claude Code
34.1%

Senior SWE-bench

A benchmark for evaluating coding agents on senior-level engineering work: building features from realistic instructions, investigating bugs that require runtime investigation, and shipping code that aligns to existing codebase conventions.

Tasteful Solve Rate
1
Image
Claude Fable 5
34.7%
2
Image
Claude Opus 5
34.7%
3
Image
GPT-5.6 Sol
34.7%
Open Benchmarks Grants

OSWorld 2.0

A benchmark for evaluating computer-use agents on long-horizon, real-world workflows: 108 authentic tasks across 31 self-hosted web environments and professional desktop applications.

By Binary Accuracy (300 steps)
1
Image
GPT-5.5 · xhigh
13%
2
Image
Claude Opus 4.7 · max
13%
3
Image
Claude Sonnet 4.6 · medium
8.3%
Open Benchmarks Grants

Agents’ Last Exam

Long-horizon professional workflows with verifiable outcomes across 55 sub-industries. 147 public tasks of a 1,500+ task corpus, sourced and validated by 300+ industry experts.

Top Submissions (Pass Rate)
1
Image
Codex · GPT 5.6-Sol · XHigh
30.6%
2
Image
Codex · GPT 5.6-Luna · XHigh
30.3%
3
Image
Kimi Code · Kimi K3 · Max
28.3%
Open Benchmarks Grants

SlopCode Bench

Measures code quality degradation in AI-assisted codebases. Tracks checkpoint solve rates, erosion (code bloat), and verbosity under realistic repo conditions.

Top Models by Iso Solve
1
Image
GPT-5.5
28.06%
2
Image
GPT-5.3-Codex
26.02%
3
Image
GPT-5.4
23.47%
Open Benchmarks Grants

Continual Learning Bench

Evaluates whether AI systems improve from prior experience across sequential, stateful tasks, measuring real in-context learning, not just raw capability.

Top Systems (Agg. Reward)
1
Image
ICL · Claude Sonnet 4.6
+0.196
2
Image
ICL · GPT-5.4
+0.189
3
Image
Claude Code · Sonnet 4.6
+0.185
Open Benchmarks Grants

Terminal-Bench 2.1

Terminal agent evaluation led by Stanford University and Laude Institute. v2.1 fixes 28 tasks from 2.0 and introduces continuous validation.

Top Submissions
1
Image
Claude Code · Claude 5 Fable
83.8%
2
Image
Codex CLI · GPT-5.5
83.1%
3
Image
Terminus 2 · Claude 5 Fable
80.4%
of
 Illution Back
Illution Front

For models that need to be right. Not just good enough.