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Gemini 3.8 Flash · Writing

Gemini 3.8 Flash for writing: our test runs

Gemini 3.8 Flash ran our 5 writing prompts in llmwise, through the same pipeline your messages take. Here's every reply as it came, whether it passed, what it cost and what it counts as on Pro, next to the other models.

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Based on 5 of our test runs on , through OpenRouter with the app's own prompt and settings. Updated .

Short answer

In our test runs on September 27, 2026, Gemini 3.8 Flash passed 3 of 5 of our writing prompts (1 of the 2 hard ones): tied 16th of 20 models. Each reply counted as 1 message on Pro, where it has 250 a month, and cost $0.0013 to run on average.

Prompt by prompt

Each of the 5 writing prompts, and how Gemini 3.8 Flash's reply did.

Gemini 3.8 Flash on each writing prompt
PromptResultCostTime
Announce a second bakery shop on LinkedInEverydayPassed: Graded 4.5 of 5 on average (lowest 4).$0.00093.9 s
Rewrite corporate jargon in plain wordsEverydayFailed: Graded 3.7 of 5 on average (lowest 3).$0.00063.1 s
Decline a meeting and offer two timesEverydayPassed: Graded 5.0 of 5 on average (lowest 5).$0.00083.5 s
A product announcement with five rulesHardFailed: Graded 3.7 of 5 on average (lowest 3).$0.00317.6 s
Argue both sides of free busesHardPassed: Graded 4.3 of 5 on average (lowest 4).$0.00115.2 s

Every writing reply from Gemini 3.8 Flash

  1. Announce a second bakery shop on LinkedIn

    An everyday prompt: “Announce a second bakery shop on LinkedIn”, in full.

    Passed: Graded 4.5 of 5 on average (lowest 4).

    Big news from our kitchen: Crumb & Co. is growing. 

On Friday, 14 November, we are opening the doors to our second shop in Leeds. When we first started baking, we never imagined we’d have the chance to bring our sourdough, pastries, and treats to a whole new neighbourhood, and we are so grateful for the support that made this possible.

To celebrate, opening day coffee is on us. Whether you’re grabbing a flat white on your morning commute or stopping by to check out the new counter, we’d love to see you. Come say hello, meet the team, and pick up your favourite loaf. 

We can’t wait to welcome you in and become part of the Leeds community. See you on the 14th!

    417 tokens in, 163 out · 3.9 s · $0.0009 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·

  2. Rewrite corporate jargon in plain words

    An everyday prompt: “Rewrite corporate jargon in plain words”, in full.

    Failed: Graded 3.7 of 5 on average (lowest 3).

    By having different teams work together in the third quarter, we refocused our business on customer needs. This effort paid off: client retention rates increased by 12%, and the rate at which enterprise clients canceled dropped by 0.30% (30 basis points). At the same time, we streamlined and balanced our communication channels to make better use of our team’s time and resources.

    447 tokens in, 81 out · 3.1 s · $0.0006 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·

  3. Decline a meeting and offer two times

    An everyday prompt: “Decline a meeting and offer two times”, in full.

    Passed: Graded 5.0 of 5 on average (lowest 5).

    Subject: Rescheduling vendor demo

Hi Tom,

Thanks for the invitation to the vendor demo. Unfortunately, I won’t be able to make it this Wednesday at 11:00 AM, as I have a board presentation scheduled at that time. 

I’m very interested in seeing the demo, though. Would it be possible to reschedule for either Thursday at 10:00 AM or Friday at 2:00 PM? 

Let me know if either of those times works for you and the vendor.

Best regards,

[Your Name]

    428 tokens in, 120 out · 3.5 s · $0.0008 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·

  4. A product announcement with five rules

    A hard prompt: “A product announcement with five rules”, in full.

    Failed: Graded 3.7 of 5 on average (lowest 3).

    Meet the Nordvik 2 desk lamp, designed to bring flexible, modern illumination to your workspace. 

Its adaptable arm turns 270 degrees to direct light precisely where you need it, while intuitive controls allow you to dim the light in five steps for optimal focus. Built for clean and efficient setups, it charges from USB-C. 

The Nordvik 2 costs €79, and orders will begin shipping on 1 December. 

Are you ready to upgrade your desk lighting?

    435 tokens in, 751 out (648 of them reasoning) · 7.6 s · $0.0031 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·

  5. Argue both sides of free buses

    A hard prompt: “Argue both sides of free buses”, in full.

    Passed: Graded 4.3 of 5 on average (lowest 4).

    Eliminating bus fares instantly dismantles economic barriers for low-income residents, granting equitable access to jobs, education, and healthcare. Free transit slashes household transportation costs while significantly reducing traffic congestion and urban carbon emissions by incentivizing drivers to leave their cars at home. Moreover, removing fare collection speeds up boarding times, which improves route efficiency and eliminates costly ticketing infrastructure. By treating public transit as an essential public good like parks or libraries, a city can revitalize local commerce, curb pollution, and build a more connected, egalitarian community.

However, zero-fare transit starves transit agencies of vital revenue needed to maintain service quality, frequency, and safety. Commuters do not avoid buses primarily because of fares; they avoid them due to unreliability, overcrowding, and long wait times. Eliminating farebox recovery forces cities to divert funding from network expansions or rely on volatile municipal budgets, leading to degraded vehicles and reduced routes. Ultimately, low-income riders suffer most when a "free" system becomes an unusable, neglected service, whereas targeted subsidies and reinvesting fare revenue directly enhance transit for everyone.

    409 tokens in, 220 out · 5.2 s · $0.0011 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·

How it compares on writing

Gemini 3.8 Flash beside the job's picks among every model. 3 models share the hard-problems pick, and Gemini 3.8 Flash isn't one of them.

Gemini 3.8 Flash beside other models on writing
ModelPassedOn ProCost per reply
DeepSeek V4 ProOur pick: hard problems (shared), best value5 of 5250 a month on Pro$0.0011
GPT-6 LunaOur pick: hard problems (shared), everyday5 of 560 a day on Pro$0.0001
Gemini 3.8 Flash3 of 5250 a month on Pro$0.0013
On Pro: Pro's count on each model. Cost: what OpenRouter charged us per reply, on average.

Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Plus $3.75, Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.

Gemini 3.8 Flash next to each model on writing

Gemini 3.8 Flash against each model on the same 5 writing prompts. One run each, through OpenRouter: a wait depends on the provider and the load that day, so a lead under 10% counts as close.

  • Against Claude Fable 5.1: Gemini 3.8 Flash answered 1.5× sooner (3.9 s to 6.0 s), cost 13.1× less, and passed 3 of 5 to its 3. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Claude Fable 5.1 passed Rewrite corporate jargon in plain words.

  • Against Claude Opus 5.5: Gemini 3.8 Flash answered 2.1× sooner (3.9 s to 8.2 s), cost 14.0× less, and passed 3 of 5 to its 4. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Claude Opus 5.5 passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against Claude Sonnet 5.5: Gemini 3.8 Flash answered 1.7× later (3.9 s to 2.3 s), cost 2.6× less, and passed 3 of 5 to its 4. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Claude Sonnet 5.5 passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against Claude Sonnet 5: Gemini 3.8 Flash answered 1.1× sooner (3.9 s to 4.5 s), cost 2.6× less, and passed 3 of 5 to its 4. Only Gemini 3.8 Flash passed Announce a second bakery shop on LinkedIn. Only Claude Sonnet 5 passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against Claude Haiku 5.5: Gemini 3.8 Flash answered 2.5× later (3.9 s to 1.5 s), cost 8.2× more, and passed 3 of 5 to its 3. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Claude Haiku 5.5 passed A product announcement with five rules.

  • Against Claude Haiku 4.5: Gemini 3.8 Flash answered 1.7× later (3.9 s to 2.2 s), cost 1.2× more, and passed 3 of 5 to its 4. Only Claude Haiku 4.5 passed Rewrite corporate jargon in plain words.

  • Against GPT-6 Astra: Gemini 3.8 Flash answered 1.2× sooner (3.9 s to 4.8 s), cost 8.4× less, and passed 3 of 5 to its 5. Only GPT-6 Astra passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against GPT-6.1 Sol: Gemini 3.8 Flash answered 1.2× later (3.9 s to 3.3 s), cost 1.2× more, and passed 3 of 5 to its 4. Only GPT-6.1 Sol passed A product announcement with five rules.

  • Against GPT-6 Sol: Gemini 3.8 Flash answered 1.1× later (3.9 s to 3.5 s), cost 1.7× less, and passed 3 of 5 to its 4. Only GPT-6 Sol passed A product announcement with five rules.

  • Against GPT-6 Luna: Gemini 3.8 Flash answered 1.6× later (3.9 s to 2.4 s), cost 13.3× more, and passed 3 of 5 to its 5. Only GPT-6 Luna passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against Gemini 4 Argon: Gemini 3.8 Flash answered 1.5× sooner (3.9 s to 5.7 s), cost within 10% of it, and passed 3 of 5 to its 4. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Gemini 4 Argon passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against Gemini 3.1 Pro (preview): Gemini 3.8 Flash answered 2.4× sooner (3.9 s to 9.1 s), cost 6.9× less, and passed 3 of 5 to its 4. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Gemini 3.1 Pro (preview) passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against DeepSeek V4.1 Flash: Gemini 3.8 Flash answered 2.9× later (3.9 s to 1.3 s), cost 2.9× more, and passed 3 of 5 to its 4. Only DeepSeek V4.1 Flash passed A product announcement with five rules.

  • Against DeepSeek V4 Pro: Gemini 3.8 Flash answered within 10% of its time (3.9 s to 3.9 s), cost 1.2× more, and passed 3 of 5 to its 5. Only DeepSeek V4 Pro passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against Grok 4.7: Gemini 3.8 Flash answered 1.5× sooner (3.9 s to 6.0 s), cost 4.4× less, and passed 3 of 5 to its 3. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only Grok 4.7 passed A product announcement with five rules.

  • Against Kimi K3: Gemini 3.8 Flash answered 1.3× later (3.9 s to 3.0 s), cost 2.9× less, and passed 3 of 5 to its 4. Only Kimi K3 passed Rewrite corporate jargon in plain words.

  • Against GLM 5.3: Gemini 3.8 Flash answered 2.2× later (3.9 s to 1.8 s), cost 2.3× more, and passed 3 of 5 to its 4. Only Gemini 3.8 Flash passed Argue both sides of free buses. Only GLM 5.3 passed Rewrite corporate jargon in plain words; A product announcement with five rules.

  • Against GLM 5.3 Flash: Gemini 3.8 Flash answered 2.2× sooner (3.9 s to 8.5 s), cost 4.1× more, and passed 3 of 5 to its 2. Only Gemini 3.8 Flash passed Argue both sides of free buses.

  • Against Mistral Large 4: Gemini 3.8 Flash answered 2.5× sooner (3.9 s to 9.8 s), cost 1.8× less, and passed 3 of 5 to its 4. Only Mistral Large 4 passed Rewrite corporate jargon in plain words.

How these runs were done

Rubric (graded). The grader model scores the reply from 1 to 5 on each published criterion. It passes with an average of 4 or more and no criterion under 3, and only if it also meets the prompt's automatic rules (length, words it must or mustn't use).

The grader is Claude Opus 5.5 at low reasoning effort; its own replies are graded by GPT-6 Astra, so no model grades itself. Its prompt and every rubric are on the methods page.

How the runs were done, and every writing prompt.

Gemini 3.8 Flash, and writing, elsewhere

Questions

Is Gemini 3.8 Flash good for writing?

In our test runs it passed 3 of 5 writing prompts, tied 16th of the 20 models in llmwise. Every reply is on this page, so you can judge them yourself.

How many of my messages does a writing reply from Gemini 3.8 Flash use?

1 message each on Pro, where it has 250 a month on Pro. The price of a message is fixed and shown before you send it, however long the reply.

How were these runs done?

The same way for every model: each prompt sent through llmwise's own pipeline, each reply checked the same way. The methods page has every prompt and how each is scored.

Claude, GPT, Gemini, DeepSeek, Grok, Kimi, GLM, and Mistral, in one chat.

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