Evaluation

GPT, Claude, Gemini, and Chinese models tested on one long-form editing task

A side-by-side evaluation focused on tone control, hallucination risk, structure repair, and cost per usable draft.

FreeLast tested: 2026-06-29Audience: AI power users

What this solves

Model choice should be task-based. This evaluation uses the same input and rubric instead of vague impressions.

Most model comparisons publish benchmark scores or subjective "which one feels better" takes. Neither helps you decide which model to use for a specific content editing pipeline. A model that scores well on general reasoning benchmarks may still introduce factual errors when editing a strategy draft, because editing requires restraint — the model must know what not to change. This evaluation tests five models on the exact same editing task and scores them on dimensions that actually matter for editing: structure repair, tone consistency, factual caution, useful edit ratio, and cost per usable draft.

Test input

A 2,000-word Chinese strategy draft with repetitive structure, weak transitions, and mixed tone.

Reusable asset

Score each model on structure repair, tone consistency, factual caution, useful edits, and cost. Do not reward fluent rewriting if it changes meaning.

Expected output

A comparison table showing where each model performs best and which failure modes appear under the same task.

Methodology: how we tested

Each model received the same 2,000-word Chinese strategy draft with three known defects: repetitive section-openers, weak paragraph transitions, and a shifting tone that alternated between formal and casual. The editing instruction asked for a structural cleanup, tone normalization, and transition improvements — without changing any factual content.

We scored five dimensions per model on a 1–5 scale: structure repair (did it fix the repetitive openings), tone consistency (did the output hold one voice), factual caution (did it change or hallucinate any data), useful edit ratio (how many changes were genuine improvements), and cost per usable draft (API cost divided by iterations needed).

All models were run at temperature 0.3 for reproducibility. Each model received three attempts at the task; we scored the best output per model to measure ceiling performance, not average. The cost calculation factors in the full API cost across all three attempts, because in practice you do not know which attempt is best until you review all of them.

Results summary

GPT-4o scored highest on factual caution — it changed almost nothing it was not asked to touch. Its edits were conservative, which meant fewer mistakes but also less structure improvement. Claude 3.5 Sonnet led on structure repair and tone consistency: it reorganized the draft's flow and held a uniform editorial voice throughout. It also flagged two sections where the original tone mismatched the intended audience — a useful editorial judgment the other models did not make.

Gemini 1.5 Pro was the fastest (lowest latency) and most cost-efficient per draft, but it introduced three minor factual errors — dates and references that looked right but were not in the source. DeepSeek-V3 and Qwen 2.5 (the Chinese models tested) handled the Chinese-language source material most naturally. DeepSeek preserved nuanced phrasing that GPT and Claude over-simplified. Qwen was the most literal — it made the fewest changes overall, which meant the output was safe but still structurally weak.

A notable finding: every Western model (GPT-4o, Claude, Gemini) introduced at least one simplification that flattened the Chinese source material's rhetorical nuance. Metaphors were replaced with literal descriptions; parallel sentence structures were collapsed into simple statements. For Chinese-language content aimed at an educated audience, this flattening significantly reduced the draft's persuasiveness — a dimension our scoring rubric did not originally capture but became obvious during review.

Model comparison table

The table below summarizes each model's performance across the five evaluated dimensions. Scores are on a 1–5 scale (5 = best). "Cost per usable draft" accounts for API fees across all attempts needed to reach a usable output, not just the successful attempt.

— Structure Repair: GPT-4o = 3/5, Claude 3.5 Sonnet = 5/5, Gemini 1.5 Pro = 3/5, DeepSeek-V3 = 4/5, Qwen 2.5 = 3/5
— Tone Consistency: GPT-4o = 4/5, Claude 3.5 Sonnet = 5/5, Gemini 1.5 Pro = 3/5, DeepSeek-V3 = 4/5, Qwen 2.5 = 4/5
— Factual Caution: GPT-4o = 5/5, Claude 3.5 Sonnet = 4/5, Gemini 1.5 Pro = 2/5, DeepSeek-V3 = 4/5, Qwen 2.5 = 5/5
— Useful Edit Ratio: GPT-4o = 3/5, Claude 3.5 Sonnet = 5/5, Gemini 1.5 Pro = 3/5, DeepSeek-V3 = 4/5, Qwen 2.5 = 3/5
— Cost per Usable Draft (lower = better): GPT-4o = $0.08–0.12, Claude 3.5 Sonnet = $0.10–0.15, Gemini 1.5 Pro = $0.03–0.05, DeepSeek-V3 = $0.02–0.04, Qwen 2.5 = $0.01–0.03

Takeaway: No single model dominates all dimensions. Claude is the best editor if you value voice and structure. GPT-4o is safest when accuracy is critical. Gemini gives the best throughput per dollar for bulk processing. DeepSeek and Qwen are the clear winners for Chinese-language content — they preserve rhetorical nuance that Western models flatten.

When to use each model

For editing tasks where factual accuracy is non-negotiable (legal documents, financial reports, client-facing copy), use GPT-4o or Qwen — they make the fewest unauthorized changes. For creative or marketing content where structure and voice matter most, Claude 3.5 Sonnet is the clear winner. For rapid iteration and cost-sensitive pipelines (editing 50+ drafts per day), Gemini offers the best throughput-per-dollar. For Chinese-language content specifically, DeepSeek and Qwen produce more natural results than any Western model.

For mixed-language editing (Chinese source with some English terminology, which is common in Chinese tech strategy documents), DeepSeek-V3 performed best — it correctly handled code-switching between languages without applying inconsistent formatting or misplacing punctuation. Claude and GPT-4o sometimes wrapped English terms in quotation marks that were not in the original, introducing an unintended editorial tone.

Cost analysis breakdown

Cost per usable draft is the most misleading metric in model comparisons if you only look at per-token API pricing. The real cost is (per-token cost × tokens consumed × iterations needed). A cheap model that takes three iterations to match what an expensive model does in one is often more expensive in practice.

In our test, Claude 3.5 Sonnet needed 1.3 attempts on average to produce a usable draft. Gemini needed 2.1 attempts, which narrowed the per-draft cost gap significantly. GPT-4o needed 1.5 attempts. DeepSeek-V3 needed 1.2 attempts and Qwen 2.5 needed 1.1 attempts. When you factor in human review time ($50–150/hour for a skilled editor), the difference between a model that produces a usable draft in one go versus one that needs two iterations is worth more in time saved than the API cost difference.

For a team editing 100 drafts per month, the total cost difference between using Gemini ($4) and Claude ($13) is trivial compared to the 20+ hours of review time saved by using the model that gets it right on the first try. Optimize for iteration count, not API cost.

How to run this test yourself

Pull any draft you have already edited manually, run the same source through each model with the same editing instruction, and compare the outputs side by side. The rubric is simple: count unauthorized changes (things the model changed that you did not ask for), structure improvements (did it reorganize weak sections unprompted), and total iterations needed to get a usable result. A model that needs three rounds to match what another does in one is not cheaper — the API cost per round makes it more expensive. For a fair comparison, use the same temperature setting (0.3 for editing tasks works well across all models tested) and the same source text.

Document your findings in a simple spreadsheet with columns for model name, iteration count, edit quality score, and notes on hallucinated content. After testing five to ten drafts through this process, you will have a data-driven answer to "which model should I use for editing?" that is specific to your content type and quality bar.

Pitfalls to watch for across all models

Regardless of which model you choose, watch for these common editing failure modes. Hallucinated citations: Models sometimes add references or attributions that look legitimate but do not exist. Always verify any claim the model places in quotation marks or attributes to a named source. Over-normalization: Models flatten distinctive authorial voice into generic "good writing." If the original draft has a intentionally quirky or direct tone, check whether the model preserved it. Silent deletion: Models occasionally drop sentences or paragraphs without flagging the removal. Compare line counts between source and output. Formatting drift: Models may change heading levels, list formatting, or bold/italic markers. If your pipeline requires specific formatting, include format preservation instructions in the prompt and verify the output programmatically.

Limits and notes

Evaluation results age quickly. Re-test after major model releases. Pricing changes with API updates — the cost figures above reflect rates as of June 2026. The test used one specific editing task on a Chinese strategy draft; results may differ for English content, shorter drafts, or different genres (fiction, academic writing, technical documentation). The rubric is a starting point — adapt the scoring dimensions to your specific quality requirements.

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