LLM Ground
Phase 1 building — August 2026

The LLM proving ground.

Reproducible, permalinked, dated model tests

LLM Ground is a public library of model capability tests where every result publishes the exact prompt, the exact parameters, and the raw, unedited output at a permanent URL. Not a leaderboard. Not another playground.

Pass rate over time

One probe, re-run monthly against the same model.

Illustrative — no live data yet
MarAprMayJunJulAug

Why not a leaderboard, a playground, or an eval platform?

Leaderboards give you an aggregate score you can't verify. Playgrounds give you a chat you can't cite. Eval platforms make you build the pipeline yourself. Nobody publishes a specific, dated, fully reproducible test of one model on one realistic task — exact prompt, exact parameters, raw output, at a permanent URL.

Swipe to see the full comparison →

CategoryCan you verify it?Permanent & citable?Task-specific?
LeaderboardsNo — aggregate scores over academic benchmarksThe ranking itself changes weeklyNo — one number, not your task
PlaygroundsN/A — the chat is ephemeralNo — closes when you close the tabSometimes, but not shareable or re-checkable
Eval platformsYes, once you build the pipeline yourselfDepends entirely on your own setupYes, if you build it
LLM GroundYes — the raw, unedited output is publishedYes — every run is a permalink, kept foreverYes — every probe is one specific, realistic task

What a proving-ground result looks like

A probe is one realistic task; a run is that probe against one model on one date. Every box below shows a piece of what a published run page contains — with mock content, clearly marked, since Phase 1 hasn't run yet.

Prompt vs. raw output

Illustrative — no live data yet

Prompt

Extract line items from this scanned invoice into strict JSON matching the schema below.

Raw output — unedited

response.json
{
  "vendor": "Acme Supply Co.",
  "invoice_number": "INV-20431",
  "line_items": [
    { "description": "Widget A", "qty": 12, "unit_price": 4.50 },
    { "description": "Widget B", "qty": 3,  "unit_price": 19.99 }
  ],
  "total": 113.97
}
Pass — schema valid

100% reproducible

Illustrative — no live data yet
reproduce.sh
curl https://openrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $OPENROUTER_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "<model-id>",
    "temperature": 0,
    "seed": 42,
    "messages": [{ "role": "user", "content": "<probe prompt>" }]
  }'

Cost & latency

Illustrative — no live data yet
Tokens (in/out)
412 / 96
Cost
$0.0031
Latency
1.8s

Regression tracker

Pass rate on one probe, re-run monthly against the same model.

Illustrative — no live data yet
92%
Mar
94%
Apr2 pts
91%
May3 pts
96%
Jun5 pts
79%
Jul17 pts
95%
Aug16 pts

Why should you believe a number on this site?

Because you don't have to take it on faith. Every claim here traces back to a raw output, a published rubric, or a versioned probe definition — the same discipline that the fabricated, unmethodologied rankings previously on this domain didn't have.

01

Raw output, never summarized away

Every run publishes the exact prompt, the exact parameters, and the model's unedited response. The score is never shown without the output that produced it.

02

Judge prompts are published too

Where a rubric needs a judge model to grade it, that judge's own prompt is public. If you don't trust the grade, you can re-grade the output yourself.

03

No rating without a method

A score with no stated process behind it is a rumor, not data. Nothing is published here that can't be traced back to a documented scoring method.

04

Runs are immutable

A published run is never edited or deleted. If a probe's definition changes, that's a new, separately versioned probe — the old runs stay exactly as they were.

Why this gets more valuable over time

Every run is permanent, so the dataset compounds monthly instead of resetting. A competitor starting next year can't manufacture a baseline they didn't record — the history is the moat.

  1. Phase 1In progress

    Curated probe library

    20–30 hand-built probes across structured extraction, code, instruction-following, and consistency, run against 8–12 current models.

  2. Phase 2Planned

    Regression tracking

    The full probe suite re-runs monthly. This is the moat: a longitudinal record of model behaviour that can't be backfilled by a competitor starting later.

  3. Phase 3Planned

    Bring your own probe

    Authors add their own probes, run them with their own key, and optionally publish to the public library after review.

  4. Phase 4Planned

    Paid tier

    Private probe suites and scheduled regression runs for teams who depend on a specific model behaving consistently.

The public probe library, every historical run, and the full methodology are free — always.

Frequently asked

These are close to the exact questions people already type into ChatGPT, Claude, or Perplexity — and today those assistants have no good source to cite, because leaderboards don't answer task-specific questions and playgrounds don't publish anything. Here's the direct answer to each one.

Q1

How do I test whether a model regressed?

Re-run the same prompt, parameters, and rubric against the new model version and compare the raw output side by side. LLM Ground automates exactly this: every probe re-runs on a fixed schedule, and each run stays permanently attached to the model version that produced it — so a regression is a dated, citable diff, not an anecdote.

Q2

What's the difference between a probe and a benchmark?

A benchmark scores a model against an academic dataset and reports one aggregate number you can't verify. A probe is a single realistic task — like extracting invoice line items into JSON — with its exact prompt, parameters, and raw output published, so you can check the claim yourself instead of trusting a score.

Q3

How is a run scored, and can I trust the score?

Each probe defines its scoring method up front: exact match, schema validation, or a rubric graded by a separate judge model whose own prompt is also published. No score is ever shown without the raw output that produced it, so a disputed grade can always be re-checked.

Q4

Why publish raw outputs instead of just a score?

A score without its underlying output is a claim you can't check. Publishing the exact prompt and the unedited response lets anyone verify a result or catch a scoring error — that difference is the entire reason this site exists instead of another leaderboard.