ZMIME
Comparison · 3 models · Updated Oct 4, 2026

GLM-4.7-FlashX vs GLM-5.3-Flash vs GPT-6 Luna

Too close to call on our weighted score (GLM-5.3-Flash 79, GPT-6 Luna 78, GLM-4.7-FlashX 61). The right pick depends on what you value most.

  1. Z.ai (Zhipu)

    GLM-4.7-FlashX

    Released Jan 19, 2026

    61/100
    • ECI—
    • Price$0.07 / $0.40
    • Context200K
  2. Z.ai (Zhipu)

    GLM-5.3-Flash

    Released Aug 26, 2026

    79/100
    • ECI151.9
    • Price$0.15 / $0.50
    • Context1M
  3. OpenAI

    GPT-6 Luna

    Released Sep 22, 2026

    78/100
    • ECI—
    • Price$0.10 / $0.50
    • Context1.05M
01 — Verdict

Too close to call

It is close. Our weighted score puts them within 1 points (GLM-5.3-Flash 79/100, GPT-6 Luna 78/100, GLM-4.7-FlashX 61/100), so choose by what matters most for your work: GLM-4.7-FlashX on price and GPT-6 Luna for long inputs. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGLM-4.7-FlashXGLM-4.7-FlashX $0.152 · GPT-6 Luna $0.20 · GLM-5.3-Flash $0.237 per 1M tokens (3:1 blend)
  • Longest contextGPT-6 LunaGPT-6 Luna 1,050,000 · GLM-5.3-Flash 1,000,000 · GLM-4.7-FlashX 200,000 tokens
  • Widest inputsGLM-5.3-FlashGLM-4.7-FlashX: Text · GLM-5.3-Flash: Text, Images, PDFs, Video · GPT-6 Luna: Text, Images, PDFs
  • Self-hostingGLM-4.7-FlashX and GLM-5.3-FlashPublishes downloadable weights
How the score is built
MeasureWeightGLM-4.7-FlashXGLM-5.3-FlashGPT-6 Luna
Price50%897983
Inputs & features30%359080
Context window20%326061
Overall100%61/10079/10078/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GLM-4.7-FlashX vs GLM-5.3-Flash vs GPT-6 Luna specifications side by side
SpecificationGLM-4.7-FlashXZ.ai (Zhipu)GLM-5.3-FlashZ.ai (Zhipu)GPT-6 LunaOpenAI
Capability
Capabilities Index (ECI)—151.9—
ECI rank—#42 of 148—
GPQA DiamondGraduate-level science questions—90.2%90.5% (best)
FrontierMath Tiers 1–3Research-level mathematics—55.8%79.0% (best)
OTIS Mock AIME 2024–2025Competition mathematics—93.9%98.9% (best)
SimpleQA VerifiedShort factual questions——41.4%
Price per million tokens
Input$0.07 (best)$0.15$0.10
Output$0.40 (best)$0.50$0.50
Cached input$0.01 (best)$0.03$0.01 (best)
Blended (3:1)$0.152 (best)$0.237$0.20
Long-context rateSame rateSame rateOver 272K: $0.20 / $0.75
Price sourceOfficial Z.AI APIOfficial Z.AI APIOfficial OpenAI API
Limits
Context window200,000 tokens1,000,000 tokens1,050,000 tokens (best)
Max output131,072 tokens (best)131,072 tokens (best)128,000 tokens
Inputs and features
TextYesYesYes
ImagesNoYesYes
PDFsNoYesYes
AudioNoNoNo
VideoNoYesNo
ReasoningYesYeslow · high · maxYeslow · medium · high · xhigh · max
Tool callingYesYesYes
Structured outputNoYesYes
Availability
WeightsOpenOpenProprietary
API model IDglm-4.7-flashxglm-5.3-flashgpt-6-luna
API providers865 (best)24
ReleasedJan 19, 2026Aug 26, 2026Sep 22, 2026
Knowledge cutoffApr 2025—May 18, 2026
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GLM-4.7-FlashX$1.50
  • GLM-5.3-Flash$2.50
  • GPT-6 Luna$2.00
04 — Questions

Which should you choose?

Which is better: GLM-4.7-FlashX, GLM-5.3-Flash or GPT-6 Luna?

It is close. Our weighted score puts them within 1 points (GLM-5.3-Flash 79/100, GPT-6 Luna 78/100, GLM-4.7-FlashX 61/100), so choose by what matters most for your work: GLM-4.7-FlashX on price and GPT-6 Luna for long inputs. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, GLM-4.7-FlashX, GLM-5.3-Flash or GPT-6 Luna?

GLM-4.7-FlashX is cheaper at $0.07 input / $0.40 output per million tokens (official Z.AI API price). GPT-6 Luna costs $0.10 input / $0.50 output per million tokens (official OpenAI API price); GLM-5.3-Flash costs $0.15 input / $0.50 output per million tokens (official Z.AI API price). At a typical mix of three input tokens to one output token, that is $0.152 per million tokens for GLM-4.7-FlashX versus $0.20 for GPT-6 Luna (1.3× as much) and $0.237 for GLM-5.3-Flash (1.6× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers all three models yet. GLM-4.7-FlashX has not been scored yet, GLM-5.3-Flash has an ECI of 151.9 and GPT-6 Luna has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GLM-4.7-FlashX, GLM-5.3-Flash and GPT-6 Luna yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.

Which has the bigger context window?

GPT-6 Luna has the largest context window at 1,050,000 tokens, against 1,000,000 for GLM-5.3-Flash and 200,000 for GLM-4.7-FlashX. Maximum output per response: GLM-4.7-FlashX up to 131,072, GLM-5.3-Flash up to 131,072, GPT-6 Luna up to 128,000 tokens.

Which can read images, PDFs, audio or video?

GLM-4.7-FlashX accepts text; GLM-5.3-Flash accepts text, images, PDFs and video; GPT-6 Luna accepts text, images and PDFs. GLM-5.3-Flash handles the widest range of inputs.

Are any of these open source?

GLM-4.7-FlashX and GLM-5.3-Flash publishes its weights and can be self-hosted; GPT-6 Luna is proprietary.

Which is newer?

GPT-6 Luna is the newest, released Sep 22, 2026. GLM-5.3-Flash came out Aug 26, 2026; GLM-4.7-FlashX came out Jan 19, 2026. Knowledge cutoff: GLM-4.7-FlashX Apr 2025, GPT-6 Luna May 18, 2026.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.