Model Comparison
GLM-5.3 Flash vs GPT-5.6 Terra
Too close to call: the best configurations, GLM-5.3 Flash (max) and GPT-5.6 Terra (ultra), are 66 Elo apart, and their 95% ranges overlap. Among 78 models, each ranked by its best configuration, GLM-5.3 Flash is #12 and GPT-5.6 Terra is #13. Cost per script: $0.022 for GLM-5.3 Flash (max) and $0.275 for GPT-5.6 Terra (ultra).
Last updated , from board data generated at 01:13 UTC.
Picks and Verdict
PickGLM-5.3 Flash
GLM-5.3 Flash (max)
Pick GLM-5.3 Flash (max) for scripts on a budget, since $0.022 a script buys the #12 model of 78, ranked by its best setting.
PickGPT-5.6 Terra
GPT-5.6 Terra (medium)
Pick GPT-5.6 Terra (medium) when you need a draft in 1.4 minutes, since ultra takes 8.0 and its range overlaps medium's.
GLM-5.3 Flash is cheaper than either GPT-5.6 Terra setting, and neither one rates above it. Ranked by best setting they're neighbors, the #12 model of 78 and the #13 model. GLM-5.3 Flash (max), its only setting on the board, costs $0.022 a script. GPT-5.6 Terra (ultra) costs $0.275, more than twelve times as much, and sits 66 Elo lower with 95% ranges that overlap, so the board can't separate the two. Against GPT-5.6 Terra (medium) the lead is 142 Elo with separate ranges, strong evidence for GLM. Ultra adds 76 Elo over medium for more than four times the money, those two ranges overlap, and it's the slowest setting on the page. If I were on Terra I'd stay at medium, where a draft comes back in 1.4 minutes against 5.2 for GLM. That speed is Terra's most useful advantage. At ultra it also leads on substance by about three and a half points and on visual cues by about two, while GLM is ahead on length, YouTube best practices, tone and craft. I'd run GLM-5.3 Flash and switch only when I need the draft in under two minutes.
Disclosure: GLM-5.3 Flash and GPT-5.6 Terra each come from the same lab as one of the judges (GLM 5.3 Flash and GPT-6.1 Sol). 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 GLM-5.3 Flash and GPT-5.6 Terra, 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 |
|---|---|---|---|---|---|---|---|
| GLM-5.3 Flash (max) | 2140 | 2093 to 2186 | 81.8 | $0.022 | 5.2 min | 37,224 | #23 |
| GPT-5.6 Terra (ultra) | 2074 | 2035 to 2113 | 81.4 | $0.275 | 8.0 min | N/A | #25 |
| GPT-5.6 Terra (medium) | 1998 | 1952 to 2041 | 80.7 | $0.062 | 1.4 min | N/A | #33 |
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. GLM-5.3 Flash (max) at Elo 2140 (range 2093 to 2186) and GPT-5.6 Terra (ultra) at Elo 2074 (range 2035 to 2113) have overlapping 95% ranges, so the board cannot separate the two best configurations.
- Lowest to Highest Thinking Level. GPT-5.6 Terra moves +76 Elo from medium to ultra, at about 4.4 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
GLM-5.3 Flash (max) scores higher on six of the nine metrics and GPT-5.6 Terra (ultra) on three. Weighted by each metric's share of the Writing Score, Length Adherence does the most to put GLM-5.3 Flash (max) ahead, with a 3.4-point lead on that metric. The weight beside each metric is its share of the Writing Score.
Consistency Across Drafts
| GLM-5.3 Flash (max) | GPT-5.6 Terra (ultra) | |
|---|---|---|
| Score spread across drafts (±) | 1.62 | 1.38 |
| Lowest script score | 80.3 Script 4 | 79.8 Script 4 |
| Highest script score | 83.8 Script 9 | 83.0 Script 6 |
| Range across scripts | 3.5 | 3.2 |
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 GLM-5.3 Flash (max) minus GPT-5.6 Terra (ultra), and the higher score is in bold.
| Script | GLM-5.3 Flash (max) | GPT-5.6 Terra (ultra) | Gap |
|---|---|---|---|
| Script 1 opinion / warning explainer | 81.1 | 81.1 | 0.0 |
| Script 2 news-analysis / skeptical explainer | 81.5 | 82.1 | -0.6 |
| Script 3 personal roadmap / opinion | 81.0 | 82.5 | -1.5 |
| Script 4 short explainer | 80.3 | 79.8 | +0.5 |
| Script 5 news-analysis / opinion explainer | 82.1 | 82.2 | -0.1 |
| Script 6 founder announcement / personal origin story | 82.9 | 83.0 | -0.1 |
| Script 7 personal technical walkthrough / agentic workflow case study | 83.5 | 80.6 | +2.9 |
| Script 8 product release announcement / personal observation | 80.8 | 80.3 | +0.5 |
| Script 9 career guide / hiring analysis | 83.8 | 81.8 | +2.0 |
| Script 10 engineering process walkthrough / presentation adaptation | 81.2 | 80.6 | +0.6 |
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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