GLM-5.3-Flash

GLM-5.3-Flash is the smaller, efficient mixture-of-experts sibling of Z.AI's GLM-5.3, positioned for coding, office documents, and financial research with autonomous tool use.

start building →

compare models

          .. .. ..... . .  .........             .. .. .   ..  ... .. ... . .
        .:+****+**+*+****+*+*++++*+++++-.      .:+++++++++++++++++++++++-++++-:.
       .-=@@@@@@@@@@@@#@####@@@@@@@#@@%+.    .:+%@@@@@%@@%@@%@%@%%@%%@%@%%@%%*.
      .-%###@####@@@###@####@@@@@##@@@+..   .:*%@@@@@@@@@@@@@@@@@@@@@@%@@%%%+:
     .+%######@#@##@@@@###@#@#####@@%-..   .-=@@@#@@@@@@@@@@@@@@@@@@@@@%%%=+..
   .:*@#@#############@###@@@####@@=:.    .-%@@@@@@@@@@@@@@@@@@@@@@@@%@@%=-.
   :*@@@####@#@#@@@@@@##@@##@@@@@@*:.   ..+%@@@@@@@@@@@@@@@@@@@%@@%@@%@%*:.
   :+*************************+*+-..    :+%@@@@@@@@@@@@@@@@@@@@@@@@@%%%*:.
    ... ..... .... ...... ... . . .   .-=@@@@@@@@@@@@@@@@@%@%@@@@@%%%%-.
                                    ..:=@@@@@@@@@@@@@@@@@@@@%%@%@@%%=-..
                                    .-%@@@@@@@@@@@@@@@@@@@%@@@%%%%%=:.
                                  .:+%@@@@@@@@@@@@@@@@@@@@@@@%@@%%*:.
                                ..:*@@@@@@@@@@@@@@@@@@@@@%@%%%%%%+:.
                                .-=%@@@@@@@@@@@@@@@@@%%@@%@@@%%=-..
                              ..-=@@@@@@@@@@@@@@@@@@@@@@@%@%%%=-..
                              :+%@@@@@@@@@@@@@@%%@@@%%%@@@%%%*:.
                            .:*%@@@@@@@@@@@@@@@@@@%%%%%@@@%%*:.
                          ..:=%@@@@@@@@@@@@@@@@@@@@@%%%%@%=+..
                          .:=@@@@@@@@@@@@@@@%@%@@@@%@@@%%=-.
                        ..-%@@@@@@@@@@@@@@@@@%%@%%@@%@%%*:.
                       .:+%@@@@@@@@@@@@@@@%%%%@@%@@@%%%*:.
                       :*%@@@@@@@@@@@@@%@@%%%@@%@%%%%%+..
                     .:=@@@@@@@@@@@@@@@@@%@%@@@@%@%%=-..
                    .-%@@@@@@@@@@@@@@@%%%@@%%@%@%%%*-.
                  .:+%%@@@@@@@@@@@@@%%%%%%@%@%%%%%*:.
                 .:*%@@@@@@@@@%@%@%%@@@@%@%%@%%%=+:.
                .:=%@@@@@@@@@%@@@@@@@%@%@%%@%%%=+.
               .-=@@@@@@@@@@@@@@%%@%%%%@@%%%%%=-..
             .:+%@@@@@@@@@@@%@%%@%%@%%@@%%%%%*:.
            .:*%@@@@@@@@@@@%@%%@@@%%%%%@%%%%+..
           .:*%@@@@@@@@@@@@%@@%%@%@@@%%@%%%+:
          .-=%@@@@@@@@@@@@@@@%%@%%%%%%%%%=-..
         :-%%@@@@@@@@@@%@%%@@@%%%%%%@@%%=:..
       .:+%@@@@@@@@@@@@@%@@%%%%@%%%%%%=*:..    . .. .. .   .    .     .  ..
      .:*%@@@@@@@@@@%@@@@%@%%@%%@%%%%=+.     .---+--+-+-+-----------------::
     .-*%%@@@@@@@@%@%@%%@%@@%@%%%%%%=-..    .+==================*=*===*=**+:.
   ..-=@@@@@@@@%%%@%%%@%@%%%%%%%%%==-.   ..:*==%%=%%==================***+...
  .:-%%@@@@@@@@%%%@@%%%@%%%%%%%%%=*:.    .-*==%==%%===%==========*===***+.
 .:+%@@@@@@@@%%%@@%@%%%@%%%%%%%%=+.    ..-=%%%=%================*==*=**-..
 .+%%%%%%@@%%@@%%%%%%%%%%%=%%%%=+.     .-============*====***==******+:..
.:-++++++-++++++-+--+-+------+-:..     .------------:---:--:--:-:::::..
      ...  .   ..   .     .              .          .. ..  ..      .

input · usd / 1m tok

$0.15

output · usd / 1m tok

$0.50

context window

1mtokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $0.15
output: $0.50
cache read: $0.03

providers

Different companies host GLM-5.3-Flash. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

Azure AI Foundry
Z.AI
Fireworks

specifications

takes text and image in, gives text outzai/glm-5.3-flash

creatorZ.AI
model typeText generation
context window1,000,000 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releasedaug 26, 2026
endpoint/v1/chat/completions

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports. see the model documentation for integration details.

try it · your prompt, this model, live

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="zai/glm-5.3-flash",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="zai/glm-5.3-flash",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

intelligence index

41.8#22 of 108 models on the gateway

coding index71.5#19 of 64
agentic index50.9#8 of 53
omniscience7.5#24 of 84
gpqa91.2%#19 of 80
humanity’s last exam39.9%#25 of 87

GPQA91.2%
AA-LCR80.0%
AutomationBench Partial60.4%
SciCode51.6%
ITBench51.2%
Multilingual LCR51.1%
Tau Banking47.2%
Humanity’s Last Exam39.9%
AnalystAgent25.0%
CritPt15.4%
GDP.pdf All-pass15.4%
Harvey LAB0.8%

Intelligence Index41.81
Omniscience Index7.47
GDPval Elo1643.87
legal index (API)39.9
coding index (API)71.5
agentic index (API)50.9
economics index (API)48.9
engineering index (API)43.8
intelligence index (API)41.8
strategy and ops index (API)45.1
finance and accounting index (API)42
healthcare and medical index (API)44.8

view source ↗all source data and breakdowns (json) ↗

each configuration is listed separately; these evaluations describe the tested model configuration, and performance and costs can differ on impossibl. unmeasured scores are omitted and api values keep their source units. last checked 2026-10-14.

compare GLM-5.3-Flash with other models

frontier labs and open weights, best-ranked firstusd / 1m tok · in / out

anthropic/claude-opus-5-5$4.00 / $20.00compare →
openai/gpt-6-astra$10.00 / $50.00compare →
meta/muse-wonder$4.00 / $20.00compare →
xiaomi/mimo-v2.6-pro$0.435 / $0.87compare →

impossibl models --all →

frequently asked questions

What is GLM-5.3-Flash?

GLM-5.3-Flash is the smaller, efficient mixture-of-experts sibling of Z.AI's GLM-5.3, positioned for coding, office documents, and financial research with autonomous tool use. It adds native visual understanding of interfaces and rendered output, using a hybrid sparse and linear attention design for accurate long-context behavior.

How much does GLM-5.3-Flash cost?

GLM-5.3-Flash costs $0.15 per million input tokens and $0.50 per million output tokens through the Impossibl API. Cache reads cost $0.03 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of GLM-5.3-Flash?

GLM-5.3-Flash has a 1,000,000-token context window through the Impossibl API.

What inputs and outputs does GLM-5.3-Flash support?

GLM-5.3-Flash accepts text and image as input. GLM-5.3-Flash returns text.

How do I use GLM-5.3-Flash through an API?

GLM-5.3-Flash is available through the Impossibl API. Use zai/glm-5.3-flash as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

follow the api quickstart →

When was GLM-5.3-Flash released?

Z.AI released GLM-5.3-Flash on August 26, 2026.

Creator release announcement ↗

this page describes GLM-5.3-Flash as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes. model descriptions and release dates, where available, use the creator sources linked under the answers above.

view the source catalog ↗model as markdown ↗report a correction →