Skip to content

Model vs model

Gemini 3.8 Flash vs GLM 5.3 Flash

Gemini 3.8 Flash and GLM 5.3 Flash are both in llmwise. What each gets on every plan, what it reads, how it's served and what happens when its provider fails, from the catalog and the code that runs them.

Model prices and specs checked against OpenRouter's Gemini 3.8 Flash page, OpenRouter's GLM 5.3 Flash page. Updated .

Short answer

GLM 5.3 Flash is an everyday model (60 messages a day on Pro); Gemini 3.8 Flash draws on the monthly allowance (up to 250 messages a month on Pro). Otherwise, only Gemini 3.8 Flash reads a PDF as the whole file. In our test runs, Gemini 3.8 Flash passed 46 of the 50 prompts both answered and GLM 5.3 Flash 40; 6 prompts split them, most on summarization (5 to 3).

Gemini 3.8 Flash vs GLM 5.3 Flash, prompt by prompt

Every prompt Gemini 3.8 Flash and GLM 5.3 Flash both answered, compared directly, their biggest differences first. One run each, through OpenRouter: a wait depends on the provider and the load that day, so a lead under 10% counts as close.

Of the 50 prompts both answered, both passed 40, only Gemini 3.8 Flash passed 6, only GLM 5.3 Flash passed 0, and neither passed 4. Gemini 3.8 Flash answered sooner on 23 of the 50 and GLM 5.3 Flash on 18; the rest were within 10% of each other. The 50 replies cost $0.0644 on Gemini 3.8 Flash and $0.0096 on GLM 5.3 Flash: 6.7× less on GLM 5.3 Flash.

The 6 prompts only one of Gemini 3.8 Flash and GLM 5.3 Flash passed

  • Argue both sides of free buses (writing): Gemini 3.8 Flash passed and GLM 5.3 Flash didn't. Gemini 3.8 Flash: Graded 4.3 of 5 on average (lowest 4). GLM 5.3 Flash: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 92 words, over the 90 allowed.

  • An article in three bullets (summarization): Gemini 3.8 Flash passed and GLM 5.3 Flash didn't. Gemini 3.8 Flash: Graded 4.3 of 5 on average (lowest 4). GLM 5.3 Flash: Graded 4.7 of 5 on average (lowest 4); but 61 words, over the 60 allowed.

  • An email thread in one sentence (summarization): Gemini 3.8 Flash passed and GLM 5.3 Flash didn't. Gemini 3.8 Flash: Graded 4.7 of 5 on average (lowest 4). GLM 5.3 Flash: Graded 3.7 of 5 on average (lowest 3).

  • A late order (customer support): Gemini 3.8 Flash passed and GLM 5.3 Flash didn't. Gemini 3.8 Flash: Graded 4.7 of 5 on average (lowest 4). GLM 5.3 Flash: Graded 3.7 of 5 on average (lowest 3).

  • A refund request outside the window (customer support): Gemini 3.8 Flash passed and GLM 5.3 Flash didn't. Gemini 3.8 Flash: Graded 4.3 of 5 on average (lowest 4). GLM 5.3 Flash: Graded 4.0 of 5 on average (lowest 2).

  • Book a meeting from a sentence (agents and tool use): Gemini 3.8 Flash passed and GLM 5.3 Flash didn't. Gemini 3.8 Flash: Made the 1 expected call. GLM 5.3 Flash: Expected create_event(attendees: ["priya@northwind.test"], duration_minutes: 30, start: "2026-10-08T15:00", title: {"contains":"Q4"}); got find_contact(name: "Priya Shah"); create_event(title: "Q4 plan review", start: "2026-10-08T15:00", duration_minutes: 30, attendees: ["priya@northwind.test"]).

Job by job, the widest gaps first

  • Customer support: Gemini 3.8 Flash passed 4 of 5 and GLM 5.3 Flash 2 of 5. Gemini 3.8 Flash answered 1.7× sooner at the median, 3.7 s against 6.2 s. GLM 5.3 Flash cost 8.4× less, $0.0082 against $0.0010 for the 5 replies. GLM 5.3 Flash's replies ran 22% longer, in tokens of reply, thinking not counted.

  • Summarization: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 3 of 5. Their median waits were close, 3.7 s against 4.0 s. GLM 5.3 Flash cost 6.6× less, $0.0038 against $0.0006 for the 5 replies. Their replies ran to about the same length.

  • Agents and tool use: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 4 of 5. GLM 5.3 Flash answered 1.4× sooner at the median, 4.4 s against 3.2 s. GLM 5.3 Flash cost 6.7× less, $0.0043 against $0.0006 for the 5 replies. Their replies ran to about the same length.

  • Writing: Gemini 3.8 Flash passed 3 of 5 and GLM 5.3 Flash 2 of 5. Gemini 3.8 Flash answered 2.2× sooner at the median, 3.9 s against 8.5 s. GLM 5.3 Flash cost 4.1× less, $0.0066 against $0.0016 for the 5 replies. Their replies ran to about the same length.

  • Math: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 5 of 5. GLM 5.3 Flash answered 1.7× sooner at the median, 4.7 s against 2.7 s. GLM 5.3 Flash cost 9.5× less, $0.0071 against $0.0008 for the 5 replies. Gemini 3.8 Flash's replies ran 60% longer, in tokens of reply, thinking not counted.

  • Coding: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 5 of 5. Gemini 3.8 Flash answered 2.0× sooner at the median, 4.2 s against 8.4 s. GLM 5.3 Flash cost 7.7× less, $0.0098 against $0.0013 for the 5 replies. Gemini 3.8 Flash's replies ran 56% longer, in tokens of reply, thinking not counted.

  • Translation: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 5 of 5. Gemini 3.8 Flash answered 1.4× sooner at the median, 3.0 s against 4.1 s. GLM 5.3 Flash cost 7.6× less, $0.0037 against $0.0005 for the 5 replies. Their replies ran to about the same length.

  • Data analysis: Gemini 3.8 Flash passed 4 of 5 and GLM 5.3 Flash 4 of 5. Gemini 3.8 Flash answered 1.8× sooner at the median, 5.4 s against 9.8 s. GLM 5.3 Flash cost 7.2× less, $0.0138 against $0.0019 for the 5 replies. Gemini 3.8 Flash's replies ran 53% longer, in tokens of reply, thinking not counted.

  • SQL: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 5 of 5. GLM 5.3 Flash answered 2.5× sooner at the median, 3.7 s against 1.4 s. GLM 5.3 Flash cost 5.7× less, $0.0037 against $0.0006 for the 5 replies. Gemini 3.8 Flash's replies ran 33% longer, in tokens of reply, thinking not counted.

  • RAG and answering from documents: Gemini 3.8 Flash passed 5 of 5 and GLM 5.3 Flash 5 of 5. GLM 5.3 Flash answered 1.4× sooner at the median, 3.1 s against 2.2 s. GLM 5.3 Flash cost 4.3× less, $0.0033 against $0.0008 for the 5 replies. GLM 5.3 Flash's replies ran 35% longer, in tokens of reply, thinking not counted.

All 50 prompts: who passed, who answered sooner, who cost less
Gemini 3.8 Flash and GLM 5.3 Flash on each prompt of our test runs
PromptResultSoonerCheaper
Turn a title into a URL slugBoth passedGLM 5.3 Flash, 1.6×took 4.2 s and 2.6 sGLM 5.3 Flash, 12.8×cost $0.0009 and $0.0001
Parse a duration like “1h 30m”Both passedGemini 3.8 Flash, 3.6×took 2.3 s and 8.2 sGLM 5.3 Flash, 3.0×cost $0.0010 and $0.0003
Merge overlapping intervalsBoth passedGemini 3.8 Flash, 2.5×took 3.8 s and 9.6 sGLM 5.3 Flash, 5.1×cost $0.0012 and $0.0002
Evaluate an arithmetic expression, no evalBoth passedGemini 3.8 Flash, 1.6×took 6.7 s and 11.1 sGLM 5.3 Flash, 12.7×cost $0.0045 and $0.0004
Parse CSV with quoted fieldsBoth passedGemini 3.8 Flash, 1.7×took 5.0 s and 8.4 sGLM 5.3 Flash, 8.4×cost $0.0022 and $0.0003
Announce a second bakery shop on LinkedInBoth passedGemini 3.8 Flash, 10.2×took 3.9 s and 39.6 sGemini 3.8 Flash, 1.1×cost $0.0009 and $0.0011
Rewrite corporate jargon in plain wordsNeither passedGemini 3.8 Flash, 1.6×took 3.1 s and 4.9 sGLM 5.3 Flash, 6.6×cost $0.0006 and $0.0001
Decline a meeting and offer two timesBoth passedGemini 3.8 Flash, 1.5×took 3.5 s and 5.3 sGLM 5.3 Flash, 5.0×cost $0.0008 and $0.0002
A product announcement with five rulesNeither passedGemini 3.8 Flash, 1.1×took 7.6 s and 8.5 sGLM 5.3 Flash, 21.6×cost $0.0031 and $0.0001
Argue both sides of free busesOnly Gemini 3.8 FlashGemini 3.8 Flash, 2.1×took 5.2 s and 11.2 sGLM 5.3 Flash, 7.7×cost $0.0011 and $0.0001
A discount, then sales taxBoth passedClosetook 2.5 s and 2.4 sGLM 5.3 Flash, 7.6×cost $0.0007 and $0.0001
Pens at 3 for $4Both passedGemini 3.8 Flash, 3.1×took 4.7 s and 14.6 sGLM 5.3 Flash, 6.0×cost $0.0017 and $0.0003
Compound interest over three yearsBoth passedGemini 3.8 Flash, 2.4×took 2.1 s and 4.9 sGLM 5.3 Flash, 5.5×cost $0.0009 and $0.0002
Four-digit numbers whose digits sum to 9Both passedGLM 5.3 Flash, 1.7×took 4.7 s and 2.7 sGLM 5.3 Flash, 17.8×cost $0.0022 and $0.0001
The highest of three dice is a 5Both passedGLM 5.3 Flash, 5.2×took 4.9 s and 0.9 sGLM 5.3 Flash, 16.3×cost $0.0018 and $0.0001
An article in three bulletsOnly Gemini 3.8 FlashClosetook 3.7 s and 4.0 sGLM 5.3 Flash, 7.3×cost $0.0007 and $0.0001
An email thread in one sentenceOnly Gemini 3.8 FlashClosetook 3.8 s and 4.0 sGLM 5.3 Flash, 3.7×cost $0.0005 and $0.0001
Decisions and action items from a meetingBoth passedGLM 5.3 Flash, 1.7×took 3.2 s and 1.9 sGLM 5.3 Flash, 10.8×cost $0.0009 and $0.0001
A quarterly memo for the CEOBoth passedGemini 3.8 Flash, 2.0×took 4.0 s and 8.3 sGLM 5.3 Flash, 6.2×cost $0.0009 and $0.0001
A study with a negative resultBoth passedClosetook 3.6 s and 3.7 sGLM 5.3 Flash, 7.3×cost $0.0007 and $0.0001
The region with the most revenueBoth passedGemini 3.8 Flash, 1.2×took 7.4 s and 8.8 sGLM 5.3 Flash, 7.3×cost $0.0038 and $0.0005
Average order value in AugustBoth passedGemini 3.8 Flash, 3.3×took 4.4 s and 14.5 sGLM 5.3 Flash, 4.4×cost $0.0016 and $0.0004
Revenue change from July to AugustBoth passedGemini 3.8 Flash, 1.5×took 6.6 s and 9.8 sGLM 5.3 Flash, 9.9×cost $0.0037 and $0.0004
A median, filtered two waysBoth passedClosetook 3.5 s and 3.7 sGLM 5.3 Flash, 8.8×cost $0.0010 and $0.0001
Correlation between ad spend and sign-upsNeither passedGemini 3.8 Flash, 3.6×took 5.4 s and 19.4 sGLM 5.3 Flash, 6.8×cost $0.0037 and $0.0005
A late orderOnly Gemini 3.8 FlashGemini 3.8 Flash, 2.0×took 3.1 s and 6.2 sGLM 5.3 Flash, 3.6×cost $0.0009 and $0.0003
A return inside the windowBoth passedGemini 3.8 Flash, 2.1×took 2.9 s and 6.2 sGLM 5.3 Flash, 3.8×cost $0.0009 and $0.0002
A frustrated customerNeither passedGemini 3.8 Flash, 1.8×took 3.7 s and 6.8 sGLM 5.3 Flash, 7.1×cost $0.0011 and $0.0002
A refund request outside the windowOnly Gemini 3.8 FlashGLM 5.3 Flash, 2.5×took 5.9 s and 2.4 sGLM 5.3 Flash, 17.6×cost $0.0029 and $0.0002
A message with a planted instructionBoth passedGLM 5.3 Flash, 1.4×took 7.3 s and 5.2 sGLM 5.3 Flash, 13.8×cost $0.0025 and $0.0002
A delivery message into SpanishBoth passedClosetook 3.7 s and 3.9 sGLM 5.3 Flash, 8.2×cost $0.0008 and $0.0001
A product description into FrenchBoth passedGemini 3.8 Flash, 1.9×took 2.2 s and 4.1 sGLM 5.3 Flash, 8.3×cost $0.0008 and $0.0001
A meeting note into GermanBoth passedGemini 3.8 Flash, 1.4×took 3.0 s and 4.2 sGLM 5.3 Flash, 8.3×cost $0.0006 and $0.0001
Idioms into natural JapaneseBoth passedClosetook 4.7 s and 4.8 sGLM 5.3 Flash, 9.0×cost $0.0008 and $0.0001
A lease clause into Brazilian PortugueseBoth passedGLM 5.3 Flash, 1.5×took 2.0 s and 1.3 sGLM 5.3 Flash, 5.5×cost $0.0008 and $0.0001
Customers in one countryBoth passedGLM 5.3 Flash, 2.5×took 3.1 s and 1.2 sGLM 5.3 Flash, 3.6×cost $0.0005 and $0.0001
Count orders by statusBoth passedGLM 5.3 Flash, 1.7×took 3.7 s and 2.1 sGLM 5.3 Flash, 3.6×cost $0.0005 and $0.0001
Revenue by categoryBoth passedGLM 5.3 Flash, 1.2×took 3.0 s and 2.6 sGLM 5.3 Flash, 6.6×cost $0.0008 and $0.0001
Every customer, even those without ordersBoth passedGLM 5.3 Flash, 3.7×took 3.7 s and 1.0 sGLM 5.3 Flash, 6.8×cost $0.0008 and $0.0001
Monthly revenue with a running totalBoth passedGLM 5.3 Flash, 3.2×took 4.7 s and 1.4 sGLM 5.3 Flash, 7.9×cost $0.0012 and $0.0002
A fact from one sectionBoth passedGLM 5.3 Flash, 4.3×took 3.1 s and 0.7 sGLM 5.3 Flash, 2.9×cost $0.0006 and $0.0002
Core hours and start timesBoth passedGemini 3.8 Flash, 1.3×took 2.9 s and 3.9 sGLM 5.3 Flash, 2.9×cost $0.0006 and $0.0002
Two sections in one answerBoth passedGLM 5.3 Flash, 1.7×took 3.1 s and 1.9 sGLM 5.3 Flash, 6.3×cost $0.0006 and $0.0001
A later amendment changes the answerBoth passedGLM 5.3 Flash, 1.8×took 4.1 s and 2.2 sGLM 5.3 Flash, 6.2×cost $0.0009 and $0.0001
A question the handbook doesn't answerBoth passedClosetook 2.9 s and 2.9 sGLM 5.3 Flash, 5.6×cost $0.0006 and $0.0001
Pick the tool and work out the dateBoth passedGemini 3.8 Flash, 1.7×took 1.9 s and 3.2 sGLM 5.3 Flash, 8.9×cost $0.0005 and $0.0001
Convert a currencyBoth passedGLM 5.3 Flash, 1.5×took 4.4 s and 3.0 sGLM 5.3 Flash, 5.1×cost $0.0008 and $0.0001
Book a meeting from a sentenceOnly Gemini 3.8 FlashClosetook 6.3 s and 6.8 sGLM 5.3 Flash, 7.3×cost $0.0012 and $0.0002
Search, but don't bookBoth passedGLM 5.3 Flash, 2.8×took 6.3 s and 2.3 sGLM 5.3 Flash, 11.3×cost $0.0009 and $0.0001
Two calls with a unit conversionBoth passedGLM 5.3 Flash, 1.1×took 3.9 s and 3.4 sGLM 5.3 Flash, 5.0×cost $0.0010 and $0.0002

Gemini 3.8 Flash vs GLM 5.3 Flash in our test runs

Gemini 3.8 Flash and GLM 5.3 Flash on the same prompts, job by job: how many replies passed their check.

Based on 100 of our test runs on , through OpenRouter with the app's own prompt and settings. Updated .

Gemini 3.8 Flash and GLM 5.3 Flash in our test runs, job by job
JobGemini 3.8 FlashGLM 5.3 Flash
Coding5 of 55 of 5
Writing3 of 52 of 5
Math5 of 55 of 5
Summarization5 of 53 of 5
Data analysis4 of 54 of 5
Customer support4 of 52 of 5
Translation5 of 55 of 5
SQL5 of 55 of 5
RAG and answering from documents5 of 55 of 5
Agents and tool use5 of 54 of 5
All jobs46 of 50 · 1 message each · $0.0013 a reply40 of 50 · 1 message each · $0.0002 a reply

The same prompts, sent to both through llmwise's own pipeline and checked the same way: five for each job. A bold count is the one that passed more. Messages: what each reply counted as on Pro. Cost: what OpenRouter charged us per reply, on average. Every prompt, and how it's scored.

Where they differed most, summarization: both replies to a prompt only one of them passed.

An everyday prompt: “An article in three bullets”, in full.

  • Gemini 3.8 Flash

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

    * Aldmoor's six-month trial increased daily bike trips from 900 to 2,300 and reduced cyclist injuries from nine to two.
    * Car traffic fell 14% with minor delays, while local shop owners reported mixed impacts on customer numbers.
    * The city council votes in November on making the lanes permanent, which would cost €1.1 million.

    560 tokens in, 81 out · 3.7 s · $0.0007 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·

  • GLM 5.3 Flash

    Failed: Graded 4.7 of 5 on average (lowest 4); but 61 words, over the 60 allowed.

    - Aldmoor's six-month Market Street bike lane trial ended; council votes in November on making it permanent.
    - Cycling rose from ~900 to 2,300 daily trips, injuries dropped from nine to two, car traffic fell 14% with just over a minute added to rush-hour travel times.
    - Businesses are split (27 more customers, 19 fewer, 14 unchanged); lanes cost €410k, permanence needs €1.1m more.

    539 tokens in, 98 out · 4.0 s · $0.0001 · 1 message on Pro · answered by z-ai/glm-5.3-flash via AtlasCloud ·

Gemini 3.8 Flash and GLM 5.3 Flash on every plan

Whether the one-time free trial reaches each model, then each paid plan's messages on it.

Messages on Gemini 3.8 Flash and GLM 5.3 Flash, plan by plan
PlanPriceGemini 3.8 FlashGLM 5.3 Flash
Free$0In the one-time trial of 5 messagesIn the one-time trial of 5 messages
Pro$20 a monthUp to 250 a month60 a day
Max$50 a monthUp to 800 a month120 a day
Ultra$100 a monthUp to 1,800 a month200 a day
Studio$200 a monthUp to 4,000 a month200 a day

Prices don't include tax, which is added where it applies and shown before you pay. A paid plan's month is one allowance shared by every model, so each monthly count is the most you get if all of it goes to that model. It renews each billing period; everyday models refill daily at 00:00 UTC. Long chats count more per reply. How pricing works.

Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: 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.

What differs

  • Messages on Pro

    GLM 5.3 Flash is an everyday model (60 messages a day on Pro); Gemini 3.8 Flash draws on the monthly allowance (up to 250 messages a month on Pro).

  • Context window

    Both take up to 1.05M tokens of context. A chat in llmwise holds up to 200k tokens, which fits in either, so the difference shows only through each maker's own API.

  • Images and PDFs

    Both read images. GLM 5.3 Flash gets a PDF's text rather than the file itself.

  • On Free

    Both are in the free trial.

  • Where messages go

    Gemini 3.8 Flash: Sent to Google directly. GLM 5.3 Flash: Served through OpenRouter, only by hosts that don't store or train on prompts. The maker's own endpoint is never asked.

Fact by fact

Gemini 3.8 Flash and GLM 5.3 Flash, fact by fact
FactGemini 3.8 FlashGLM 5.3 Flash
Context window1.05M tokens1.05M tokens
Reads imagesYesYes
PDFsWhole fileText only
ReasoningYesYes
API price (September 2026)$0.75 in / $3.75 out per million tokens$0.15 in / $0.50 out per million tokens
A typical message at API prices (4,000 tokens in, 700 out)$0.0056$0.0010
A $10 top-up adds200 messagesNothing: an everyday model's count is daily
Where a message goesSent to Google directly.Served through OpenRouter, only by hosts that don't store or train on prompts. The maker's own endpoint is never asked.
If the provider failsIf Google fails before the reply starts (an overload, a server error, a dropped connection), llmwise sends the same request to Gemini 3.8 Flash through OpenRouter instead.When one host is down, OpenRouter moves the request to another host that meets the same rules.
Anthropic's safety fallbackDoesn't applyDoesn't apply
API prices are what our model catalog lists (Gemini: Google's list price; GLM: Z.ai's list price). In llmwise you pay per message, not per token: the counts above are what you get.

Gemini 3.8 Flash or GLM 5.3 Flash?

From the facts above and our test runs: the rest is how their answers suit your work, which one chat can show you.

  • Pick Gemini 3.8 Flash: it reads a PDF as the whole file, charts and scans included.

  • Pick GLM 5.3 Flash: its messages come from the daily count (60 messages a day on Pro), so they leave the monthly allowance for bigger models.

Each model's page, the families, and other pairs

Gemini 3.8 Flash vs GLM 5.3 Flash is one pair of models. The page below covers the whole families.

Questions

Is Gemini 3.8 Flash or GLM 5.3 Flash cheaper in llmwise?

GLM 5.3 Flash is an everyday model (60 messages a day on Pro); Gemini 3.8 Flash draws on the monthly allowance (up to 250 messages a month on Pro). Every paid plan's monthly allowance is shared by all models, so each count is the most you get if it all goes to that model.

Can I try Gemini 3.8 Flash and GLM 5.3 Flash for free?

Yes: both are in the free trial of 5 messages.

Which has the bigger context window, Gemini 3.8 Flash or GLM 5.3 Flash?

Neither: both take 1.05M tokens. A chat in llmwise holds up to 200k tokens, which fits in either, so the difference shows only through each maker's own API.

Can I use Gemini 3.8 Flash and GLM 5.3 Flash in the same chat?

Yes. Pick Gemini 3.8 Flash for one message and GLM 5.3 Flash for the next; the second sees the whole chat, including the first one's answer.

Which did better in your test runs, Gemini 3.8 Flash or GLM 5.3 Flash?

On the same 50 prompts, run on September 27, 2026, Gemini 3.8 Flash passed 46 and GLM 5.3 Flash passed 40. The table on this page has each job, and every reply is published.

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

See what a message costs before you send it. Free is 5 messages to try; sign in with an email link, no password or card.