Model Comparison
Claude Opus 4.8 vs Grok 4.6
Too close to call: the best configurations, Claude Opus 4.8 (max effort) and Grok 4.6 (high), are 35 Elo apart, and their 95% ranges overlap. Among 78 models, each ranked by its best configuration, Claude Opus 4.8 is #15 and Grok 4.6 is #19. Cost per script: $1.23 for Claude Opus 4.8 (max effort) and $0.156 for Grok 4.6 (high).
Last updated , from board data generated at 01:13 UTC.
Picks and Verdict
PickClaude Opus 4.8
Claude Opus 4.8 (max effort)
Pick Claude Opus 4.8 (max effort) when clean prose matters more than voice, since it leads Grok by almost three points on Writing Craft & Clarity and holds the length better, at $1.23 a script.
PickGrok 4.6
Grok 4.6 (high)
Pick Grok 4.6 (high) for most scripts, since it sits 35 Elo from Opus at max effort with overlapping ranges and costs $0.156 instead of $1.23.
Grok 4.6 has a single setting on the board, and it's the one I'd run for most scripts. At high, the one level name both models use, it sits 110 Elo above Claude Opus 4.8, and the 95% ranges don't overlap. Opus needs max effort to catch up. There it rates 35 Elo above Grok 4.6 (high) with overlapping ranges, so the board cannot separate them, and that setting is what makes Claude Opus 4.8 the #15 model of 78 against the #19 model for Grok 4.6. Catching up is expensive: $1.23 a script against $0.156, close to eight times the price, and almost ten minutes of waiting against five. Opus at max effort does write cleaner prose, almost three points ahead on Writing Craft & Clarity, and it holds the length four points better. At high it's quick, under a minute and a half, but it costs a little more than Grok. Grok also leads both Opus settings on tone and substance, the two heaviest metrics in the score. I'd pay for Opus at max effort only when clean prose matters more to me than voice.
Disclosure: Claude Opus 4.8 comes from the same lab as one of the four judges, Claude Opus 5.5. The other three sit outside its lab, so it is never scored by its own lab alone (how the panel works). The judge analysis measures how much each judge favors its own lab.
How to Read the Writing Score, Writing Elo and 95% Ranges
Writing Score and Writing Elo. The Writing Score (0 to 100) is the weighted average of the nine metric scores: seven from the judges, Length Adherence from code and the Slop Score half from each. The Writing Elo is a rating from pairwise comparisons: on each script, each configuration's average across its drafts is compared with every other configuration's, and gaps within the draft-to-draft variation count as draws. Elo rewards winning often, so the two can put configurations in a different order.
Elo ranges. Each 95% range shows how far a configuration's Elo could move if the drafts had come out slightly differently. It comes from resampling every configuration's recorded draft scores on each reference script and ranking again. Comparing two separate ranges does not test the Elo gap between them: ranges far apart are strong evidence for the order, and overlapping ranges do not mean a tie. The reference scripts stay fixed, so the ranges say nothing about new scripts. The methodology page has the full description.
All Thinking Levels of Both Models
Every ranked configuration of Claude Opus 4.8 and Grok 4.6, scored on the same 10 scripts by the same four judges.
- Each row is one configuration: the model at one thinking level. The dot is its Writing Elo, a rating from pairwise comparisons of the scores on each script, and the bar is its 95% range: how far that Elo could move if the drafts had come out slightly differently.
- When two bars overlap, the board cannot order those two configurations. Bars far apart are strong evidence for the order.
- The table under the chart lists the same configurations in the same order and adds the Writing Score (the 0 to 100 consensus of the judges and code), cost, time and configuration rank (the place among all configurations on the board).
Shaded rows are the configurations chosen for the metric comparison below.
| Configuration | Writing Elo | 95% Range | Writing Score | Cost / Script | Time / Script | Reasoning Tokens | Configuration Rank |
|---|---|---|---|---|---|---|---|
| Claude Opus 4.8 (max effort) | 2013 | 1977 to 2047 | 80.7 | $1.23 | 9.8 min | N/A | #30 |
| Grok 4.6 (high) | 1978 | 1930 to 2023 | 80.3 | $0.156 | 5.2 min | 18,588 | #36 |
| Claude Opus 4.8 (high) | 1868 | 1827 to 1905 | 79.3 | $0.193 | 1.4 min | N/A | #44 |
Cost is one script at the API list price of the route used, uncached and without judging. Time is the average for one accepted script, retries included. N/A under Reasoning Tokens means the board has no separate reasoning count for that route.
Computed Findings Across Thinking Levels
Each finding is computed from the configurations above. Where two 95% ranges overlap, the board cannot order those two configurations.
- Best Configurations Head to Head. Claude Opus 4.8 (max effort) at Elo 2013 (range 1977 to 2047) and Grok 4.6 (high) at Elo 1978 (range 1930 to 2023) have overlapping 95% ranges, so the board cannot separate the two best configurations.
- Same Level Name, Side by Side. At high, the one level name both models use, Grok 4.6 has the higher Writing Elo: 1978 against 1868. Their 95% ranges do not overlap there. Level names come from each provider, so the same name does not promise the same reasoning budget.
- Cheapest Configuration Overlapping the Top One. Grok 4.6 (high), at $0.156 per script, is the cheapest configuration whose 95% range overlaps that of Claude Opus 4.8 (max effort), at $1.23 per script: 1930 to 2023 against 1977 to 2047, so the board cannot separate them. Claude Opus 4.8 (max effort) costs about 7.9 times as much per script.
- Cheapest Claude Opus 4.8 Configuration Above Grok 4.6's Best. The cheapest Claude Opus 4.8 configuration with a higher Writing Elo than Grok 4.6 (high), at Elo 1978 and $0.156 per script, is Claude Opus 4.8 (max effort), at Elo 2013 and $1.23 per script. Their 95% ranges overlap, so the board cannot separate them. It costs about 7.9 times as much per script.
- Lowest to Highest Thinking Level. Claude Opus 4.8 moves +145 Elo from high to max effort, at about 6.4 times the cost per script.
Two Chosen Configurations Compared
Pick one configuration of each model to compare their metric scores, consistency across drafts and per-script scores. Each menu starts on the model's best configuration.
Scores by Metric
Claude Opus 4.8 (max effort) scores higher on seven of the nine metrics and Grok 4.6 (high) on two. Weighted by each metric's share of the Writing Score, Writing Craft & Clarity does the most to put Claude Opus 4.8 (max effort) ahead, with a 2.7-point lead on that metric. The weight beside each metric is its share of the Writing Score.
Consistency Across Drafts
| Claude Opus 4.8 (max effort) | Grok 4.6 (high) | |
|---|---|---|
| Score spread across drafts (±) | 2.02 | 1.82 |
| Lowest script score | 77.5 Script 4 | 78.5 Script 3 |
| Highest script score | 83.1 Script 6 | 82.8 Script 6 |
| Range across scripts | 5.6 | 4.3 |
Spread is how much the Writing Score moves between a configuration's drafts, and lower is steadier. Green marks the better number in each row.
Scores by Script
Writing Score on each reference script. Gap is Claude Opus 4.8 (max effort) minus Grok 4.6 (high), and the higher score is in bold.
| Script | Claude Opus 4.8 (max effort) | Grok 4.6 (high) | Gap |
|---|---|---|---|
| Script 1 opinion / warning explainer | 80.2 | 81.6 | -1.4 |
| Script 2 news-analysis / skeptical explainer | 80.6 | 80.8 | -0.2 |
| Script 3 personal roadmap / opinion | 79.3 | 78.5 | +0.8 |
| Script 4 short explainer | 77.5 | 80.2 | -2.7 |
| Script 5 news-analysis / opinion explainer | 80.3 | 81.1 | -0.8 |
| Script 6 founder announcement / personal origin story | 83.1 | 82.8 | +0.3 |
| Script 7 personal technical walkthrough / agentic workflow case study | 82.5 | 79.0 | +3.5 |
| Script 8 product release announcement / personal observation | 82.5 | 79.7 | +2.8 |
| Script 9 career guide / hiring analysis | 82.0 | 80.4 | +1.6 |
| Script 10 engineering process walkthrough / presentation adaptation | 78.9 | 79.1 | -0.2 |
Scorecards and Thinking Pages
Each configuration name in the table above opens its own scorecard.
Compare With Another Model
Pick a second model. A pair with its own written match-up opens that page, and any other pair opens in the comparison tool.
Nearby Match-Ups by Best Writing Elo
Every configuration wrote five drafts for each of the same 10 briefs, from the same prompt. Generation was closed-book, with the prompt as the only source and no web search or other tools. Each judge scores every draft once: Claude Opus 5.5 at medium effort through the Claude Code subscription, GPT-6.1 Sol at medium reasoning through the Codex CLI, GLM 5.3 Flash through OpenRouter, and Jev 1.13, a typed judge from TypeSafe that answers each metric as a multiple-choice question. The channel's finished script is their reference for the voice, and it gets no score on the board itself.
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