Drag each answer to line up with its matching prompt
SWE-bench
Multi-environment task completion across web, OS, and database tasks, measuring operational breadth
AgentBench
Realistic web navigation tasks on simulated live websites, measuring browser agent capability
WebArena
Autonomous GitHub issue resolution: produce a patch that makes a real test suite pass, measuring code editing depth
SWE-bench measures code-editing depth on real GitHub issues, AgentBench measures breadth across many environments, and WebArena measures realistic web navigation.
Imagine you want to test how good a new employee is. One test hands them a broken piece of software and a list of failing checks, and says fix it so the checks pass. That is SWE-bench, and it measures depth in one hard skill: writing real code. Another test sends them through many different rooms, a kitchen, a workshop, an office, and gives each room a small job. That is AgentBench, and it measures breadth across many situations. A third test drops them onto a fake but lifelike website and asks them to book a flight or find a product. That is WebArena, and it measures whether they can click around the web like a person. Each test asks a different question, so a worker who aces one can still flop on another.
Concept explanation~2 min read
Everything you need to truly understand this topic: intuition, mechanics, step by step explanation, code, formulas, and worked example. Click to expand.
Concept explanation~2 min read
Everything you need to truly understand this topic: intuition, mechanics, step by step explanation, code, formulas, and worked example. Click to expand.
Agent benchmarks are easy to confuse because every one of them reports a percentage and every percentage looks like an overall grade. The interview skill is to resist that framing. Each benchmark deliberately isolates a different competence, and a strong number on one says almost nothing about the others. An agent that resolves seventy percent of coding issues may navigate a shopping site no better than chance, because the underlying skills barely overlap.
The clean mental model is a matrix of axes rather than a single leaderboard. SWE-bench is depth on real code. AgentBench is breadth across many environments. WebArena is browser grounding. GAIA is general assistant reasoning. tau-bench is tool use under policy with a simulated user. Once you map each name to its axis, the match-pairs question becomes mechanical, and the senior follow-ups about contamination and benchmark trust open up naturally.
The reason the field built so many benchmarks is that agents are systems, not models. A static question-answering dataset can grade a model in isolation, but an agent only exists when an LLM is wrapped in a loop with tools, state, and an environment. You cannot test that with a multiple-choice quiz. You have to put the whole system into a task, let it act over many steps, and check whether the world ended up in the goal state. Each benchmark below is a different world with a different goal, and that is exactly why they cannot be collapsed into one ranking.
SWE-bench: verifiable code-editing depth
SWE-bench is the depth benchmark for autonomous software engineering. Each task is a real issue pulled from a popular open source Python repository, such as Django or scikit-learn, paired with the full codebase as it existed at that moment. The agent must produce a patch that resolves the issue. This is genuinely hard, because the agent has to locate the relevant code across a large repository, understand the intended behaviour, and edit it without breaking anything else.
What makes it strict is the scoring. The patch is applied and the project's own hidden test suite is run, including tests written specifically for that issue that the agent never sees. The task counts as solved only if the relevant tests pass and no previously passing tests break. There is no credit for plausible-looking diffs, which is why the benchmark resists the reward hacking that plagues judge-based scores. A model cannot talk its way to a high number; the code either works or it does not.
The original release had problems: some issues were ambiguous, some were effectively unsolvable from the issue text alone, and some appeared in model training data because the repositories are public. The community responded with SWE-bench Verified, a human-filtered subset where engineers confirmed each task is well specified and solvable. That Verified number is the one most frontier launches now quote, and knowing the distinction is a quick way to show benchmark literacy. There are also harder variants such as SWE-bench Multimodal and live, continuously refreshed sets that fight contamination by using issues filed after a model's training cutoff.
Situations where this technique stops working.
2–4 min · Everything important, quickly.
| Benchmark | What it measures | Task type | Scoring signal |
|---|---|---|---|
| SWE-bench | Code-editing depth | Resolve a real GitHub issue | Hidden test suite passes |
| AgentBench | Operational breadth | Tasks across 8 environments | Per-environment success rate |
| WebArena | Browser navigation | Goals on self-hosted websites | Functional task completion |
| GAIA | General assistant reasoning | Multi-step questions needing tools | Exact-match answer correctness |
| tau-bench | Tool use under policy | Customer-service dialogue | Goal met plus policy followed |
Real products, models, and research that use this idea.
- SWE-bench Verified is the headline coding metric in frontier model launches, with GPT-5.5, Claude Opus 4.7, and Gemini 3.1 Pro all reporting resolution rates on it.
- Cognition's Devin was first marketed on a SWE-bench resolution percentage, which set the template for agent coding claims.
What an interviewer would ask next. Try answering before peeking at the approach.
QWhy did the community shift from the original SWE-bench to SWE-bench Verified, and what does that say about benchmark trust?
Discuss training-data contamination and ambiguous or unsolvable issues in the original set. Verified is a human-filtered subset that removes those, raising confidence that a score reflects real capability rather than memorisation.
Red flags & common mistakes
The phrases that signal junior thinking. Click to expand.
Red flags & common mistakes
The phrases that signal junior thinking. Click to expand.
Treating all agent benchmarks as interchangeable scores. Each one isolates a different axis, so a high SWE-bench number says nothing about web navigation or broad task coverage.
60 second bullets to scan on the way to the call.
State what SWE-bench measures and why its scoring is binary.
Explain why AgentBench is described as a breadth benchmark.
Primary sources. Browse if you want the original framing.
Same topic, related formats. Practice these next.