Model Comparison
Claude Haiku 5.5 vs Claude Opus 4.8
Too close to call: the best configurations, Claude Haiku 5.5 (max effort) and Claude Opus 4.8 (max effort), have the same Writing Elo, 1988. Among 81 models, each ranked by its best configuration, Claude Haiku 5.5 is #17 and Claude Opus 4.8 is #18. Cost per script: $0.103 for Claude Haiku 5.5 (max effort) and $1.23 for Claude Opus 4.8 (max effort).
Last updated , from board data generated at 16:59 UTC.
Picks and Verdict
PickClaude Haiku 5.5
Claude Haiku 5.5 (xhigh)
Pick Claude Haiku 5.5 (xhigh) for regular use: $0.029 a script, under four minutes, and a result the board can't separate from Claude Opus 4.8 (high) at $0.193.
PickClaude Opus 4.8
Claude Opus 4.8 (max effort)
Pick Claude Opus 4.8 (max effort) when the hook and the structure carry the script, with 80.4 on YouTube Best Practices against 76.8 for Haiku's best, at $1.23 a script.
Claude Haiku 5.5 (max effort) and Claude Opus 4.8 (max effort) share the top Writing Elo on this page, 1988 each, and Haiku costs about a twelfth as much. Their 95% ranges overlap, so the board can't separate the two settings that make Haiku the #17 model of 81 and Opus the #18 model. One step down, Haiku still looks good. Claude Haiku 5.5 (xhigh), at $0.029, rates 68 Elo above Claude Opus 4.8 (high) for about a seventh of the price, and the ranges overlap, so the board can't separate them. It gives up 72 Elo to Haiku's own max effort setting, and those ranges just overlap too. Below xhigh Haiku falls off quickly. Opus at max effort leads on YouTube Best Practices by close to four points and on hooks by two, while Haiku's best is ahead on substance and the Slop Score. Haiku at max effort is also the slowest option here, at nearly 13 minutes. I'd run Haiku: max effort when the draft can wait, xhigh when it can't. If hooks and structure matter most and money doesn't, Opus at max effort.
Disclosure: both models come from the same lab as one of the four judges, Claude Opus 5.5. The other judges sit outside that lab, so neither is 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 Haiku 5.5 and Claude Opus 4.8, 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 | Configuration Rank |
|---|---|---|---|---|---|---|
| Claude Haiku 5.5 (max effort) | 1988 | 1950 to 2021 | 80.8 | $0.103 | 12.6 min | #33 |
| Claude Opus 4.8 (max effort) | 1988 | 1950 to 2034 | 80.7 | $1.23 | 9.8 min | #34 |
| Claude Haiku 5.5 (xhigh) | 1916 | 1871 to 1953 | 80.0 | $0.029 | 3.6 min | #44 |
| Claude Opus 4.8 (high) | 1848 | 1811 to 1889 | 79.3 | $0.193 | 1.4 min | #48 |
| Claude Haiku 5.5 (high) | 1703 | 1663 to 1741 | 78.0 | $0.012 | 1.5 min | #56 |
| Claude Haiku 5.5 (medium) | 1615 | 1555 to 1664 | 76.7 | $0.0067 | 0.8 min | #67 |
| Claude Haiku 5.5 (low) | 1498 | 1445 to 1537 | 75.2 | $0.0045 | 0.5 min | #79 |
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.
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 Haiku 5.5 (max effort) and Claude Opus 4.8 (max effort) have the same Writing Elo, 1988. Their 95% ranges overlap, so the board cannot separate the two best configurations.
- Lowest Thinking Levels Head to Head. At their lowest thinking levels, Claude Opus 4.8 (high) at Elo 1848 and $0.193 per script leads Claude Haiku 5.5 (low) at Elo 1498 and $0.0045 per script by 350 Elo. Their 95% ranges do not overlap.
- Same Level Name, Side by Side. Across the level names both models use, Claude Opus 4.8 leads at high; they tie at max. The 95% ranges do not overlap at high. Level names come from each provider, so the same name does not promise the same reasoning budget.
- Cheapest Configuration Overlapping the Top One. Claude Haiku 5.5 (xhigh), at $0.029 per script, is the cheapest configuration whose 95% range overlaps that of Claude Haiku 5.5 (max effort), at $0.103 per script: 1871 to 1953 against 1950 to 2021, so the board cannot separate them. Claude Haiku 5.5 (max effort) costs about 3.6 times as much per script.
- Lowest to Highest Thinking Level. Claude Haiku 5.5 moves +490 Elo from low to max effort, at about 23 times the cost per script. Claude Opus 4.8 moves +140 Elo from high to max effort, at about 6.4 times the cost per script.
Writing Elo at Each Shared Level Name
| Level | Claude Haiku 5.5 | Claude Opus 4.8 | Gap | 95% Ranges |
|---|---|---|---|---|
| high | 1703 | 1848 | -145 | Separate |
| max | 1988 | 1988 | +0 | Overlap |
Gap is Claude Haiku 5.5 minus Claude Opus 4.8 at the same level name, using each model's highest-rated configuration at that level.
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 Haiku 5.5 (max effort) scores higher on five of the nine metrics and Claude Opus 4.8 (max effort) on four. Weighted by each metric's share of the Writing Score, Substance, Accuracy & Value does the most to put Claude Haiku 5.5 (max effort) ahead, with a 3.6-point lead on that metric. The weight beside each metric is its share of the Writing Score.
Consistency Across Drafts
| Claude Haiku 5.5 (max effort) | Claude Opus 4.8 (max effort) | |
|---|---|---|
| Score spread across drafts (±) | 1.55 | 2.02 |
| Lowest script score | 78.2 Script 10 | 77.5 Script 4 |
| Highest script score | 82.6 Script 4 | 83.1 Script 6 |
| Range across scripts | 4.4 | 5.6 |
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 Haiku 5.5 (max effort) minus Claude Opus 4.8 (max effort), and the higher score is in bold.
| Script | Claude Haiku 5.5 (max effort) | Claude Opus 4.8 (max effort) | Gap |
|---|---|---|---|
| Script 1 opinion / warning explainer | 80.3 | 80.2 | +0.1 |
| Script 2 news-analysis / skeptical explainer | 80.7 | 80.6 | +0.1 |
| Script 3 personal roadmap / opinion | 80.8 | 79.3 | +1.5 |
| Script 4 short explainer | 82.6 | 77.5 | +5.1 |
| Script 5 news-analysis / opinion explainer | 81.7 | 80.3 | +1.4 |
| Script 6 founder announcement / personal origin story | 81.1 | 83.1 | -2.0 |
| Script 7 personal technical walkthrough / agentic workflow case study | 80.0 | 82.5 | -2.5 |
| Script 8 product release announcement / personal observation | 81.3 | 82.5 | -1.2 |
| Script 9 career guide / hiring analysis | 81.5 | 82.0 | -0.5 |
| Script 10 engineering process walkthrough / presentation adaptation | 78.2 | 78.9 | -0.7 |
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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