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AI Choice Engine

Model comparison

GLM 5.3 vs GLM 5.3 Flash

Two Z.ai tiers compared on the figures that decide which one a workload actually needs.

Recorded profile verification October 2, 2026Individual provider fields may changeEvidence confidence: Medium — see receipts below

Z.ai

GLM 5.3

Frontier · Open weights

vs

Z.ai

GLM 5.3 Flash

Balanced · Open weights

AI model capability comparison
SpecificationGLM 5.3GLM 5.3 Flash
ProviderZ.aiZ.ai
TierFrontierBalanced
Context window1MWinner: 1.05M
Max output131KNot verifiedUnverified
Input / 1M tokens$1.40Winner: $0.15
Output / 1M tokens$4.40Winner: $0.50
WeightsOpenOpen
Parameters753B total (MoE; active count not verified)320B total / 18B active (MoE)
Reasoning levelslow, high, maxlow, high, max
Modalitiestexttext, image, video, file
LicenseGLM-5.3 License (custom)MIT
API model idglm-5.3glm-5.3-flash
ReleasedAugust 14, 2026August 26, 2026
Artificial Analysis Intelligence Index [max] · source date GLM 5.3: 2026-10-0145Not verifiedUnverified
Artificial Analysis Intelligence Index · source date GLM 5.3 Flash: 2026-10-01Not verifiedUnverified42
Terminal-Bench 2.1 · source date GLM 5.3: 2026-08-14, GLM 5.3 Flash: 2026-08 (comparability not verified)88.284.3
DeepSWE 1.1 · source date GLM 5.3: 2026-08-14, GLM 5.3 Flash: 2026-08 (comparability not verified)66.963.4
Humanity's Last Exam · source date GLM 5.3: 2026-08-14, GLM 5.3 Flash: 2026-08 (comparability not verified)62.555.3

Dates beside benchmark scores refer to the linked source’s publication or capture date unless that source explicitly states when it measured the result. A shared URL alone does not establish comparable runs; unverified setups are marked. Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

Where each score comes from, and how far it can be compared across models.

Pricing tiers

GLM 5.3: Z.ai token API $1.40/$4.40 per MTok; cached input $0.26. Cache storage is listed as limited-time free, with no verified end date. Coding Plan points are separate: off-peak/weekend calls consume half the standard points. API docs advertise 1M context and specify a 131,072 output ceiling.

GLM 5.3 Flash: Z.ai API $0.15/$0.50 per MTok; cached input $0.03 and limited-time free cache storage. Hosted docs advertise 1M context and 128K output; the checkpoint config sets 1,048,576 context. An exact endpoint-specific numeric output ceiling is not separately verified. FlashX is a distinct $0.37/$1.25 endpoint; third-party prices require their own checks.

FrontierOpen weightsRecord checked October 2, 2026

GLM 5.3

Z.ai's text-only GLM flagship, with a 753B-total MoE checkpoint and always-enabled reasoning. Published benchmark figures identify particular harnesses and settings.

Best for

  • Coding Plan subscribers
  • Long-horizon coding
  • Chinese + English

Watch out

Custom licence: model-as-a-service operators whose licensee/affiliate aggregate revenue exceeds $10B in any consecutive 12 months require Z.AI security review before commercial use; the definition excludes embedded end-user features/harnesses and mere relays. Keep attribution/permission notices. Reasoning defaults to max; disabling it fails. Accounts that ever subscribed to Coding Plan, including expired subscriptions, currently have Model API access only through the Chat Completions-compatible protocol. Active parameter count and exact initial weight-publication day remain unverified.

BalancedOpen weightsRecord checked October 2, 2026

GLM 5.3 Flash

Z.ai's multimodal MIT-licensed 320B/18B MoE checkpoint and hosted Flash endpoint, with always-enabled reasoning and publisher coding/agent evaluations.

Best for

  • Cost-efficient long-context
  • Multimodal input
  • Coding agents

Watch out

The 320B weights require substantial hardware; memory depends on quantization, runtime and context. Effort low/high/max defaults to max. Flash is on Coding Plan with three times GLM-5.3 quota; FlashX is not on the plan. Half-point off-peak/weekend use applies to plan quota, not per-token API prices. Publisher evaluation generation budgets are not hosted API output caps.

When the cheaper one wins

GLM 5.3 Flash is cheaper on output at $0.50 per million tokens against $4.40 for GLM 5.3 — about 8.8×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. On DeepSWE 1.1, GLM 5.3 Flash is 63.4% Pass@1 at $0.48/task versus GLM 5.3 at 69% / $3.99/task. This compares standard short-context token rates, not total cost per accepted task. Include input, cache, context tiers, schedules, retries and review in your pilot.

Run the model picker

Evidence confidence: Medium

How strong and complete the evidence behind this comparison is — not a prediction of which model is better.

  • Pricing verified on both sides — Input and output rates are verified for both models.
  • 4/5 core specs verified on both sides — Not published for at least one side: max output.
  • No directly aligned benchmark setup — No benchmark has matching cited sources, source dates, units, effort and recorded run details on both models.
  • Verified within the last 90 days — Older of the two catalog checks was 24 days ago.
  • Both models carry source citations — Each side has at least two catalog sources on record.

Source receipts

Each catalog figure was checked against the provider or an independent second source on the date shown.

Related comparisons

Diving deeper on one model? GLM 5.3 · GLM 5.3 Flash

Common questions

GLM 5.3 vs GLM 5.3 Flash

Answered from the verified figures on this page rather than general guidance.

Is GLM 5.3 or GLM 5.3 Flash cheaper for input?
GLM 5.3 Flash is cheaper at $0.15 per million input tokens, against $1.40 for GLM 5.3 — roughly 9.3× the price. Estimate both input and output token volume for your workload. These are base rates; GLM 5.3: Z.ai token API $1.40/$4.40 per MTok; cached input $0.26. Cache storage is listed as limited-time free, with no verified end date. Coding Plan points are separate: off-peak/weekend calls consume half the standard points. API docs advertise 1M context and specify a 131,072 output ceiling. GLM 5.3 Flash: Z.ai API $0.15/$0.50 per MTok; cached input $0.03 and limited-time free cache storage. Hosted docs advertise 1M context and 128K output; the checkpoint config sets 1,048,576 context. An exact endpoint-specific numeric output ceiling is not separately verified. FlashX is a distinct $0.37/$1.25 endpoint; third-party prices require their own checks.
Is GLM 5.3 or GLM 5.3 Flash cheaper for output?
GLM 5.3 Flash is cheaper at $0.50 per million output tokens, against $4.40 for GLM 5.3 — roughly 8.8× the price. Estimate both input and output token volume for your workload. These are base rates; GLM 5.3: Z.ai token API $1.40/$4.40 per MTok; cached input $0.26. Cache storage is listed as limited-time free, with no verified end date. Coding Plan points are separate: off-peak/weekend calls consume half the standard points. API docs advertise 1M context and specify a 131,072 output ceiling. GLM 5.3 Flash: Z.ai API $0.15/$0.50 per MTok; cached input $0.03 and limited-time free cache storage. Hosted docs advertise 1M context and 128K output; the checkpoint config sets 1,048,576 context. An exact endpoint-specific numeric output ceiling is not separately verified. FlashX is a distinct $0.37/$1.25 endpoint; third-party prices require their own checks.
Which has the larger context window, GLM 5.3 or GLM 5.3 Flash?
GLM 5.3 Flash accepts 1.05M tokens against 1M for GLM 5.3. This only matters if you routinely send very long documents or large codebases.
Do GLM 5.3 and GLM 5.3 Flash support the same reasoning levels?
Both expose these named effort settings: "low", "high", "max". The same labels do not guarantee equal compute budgets or behavior across providers. Compare quality, latency and cost on your own tasks.
Should I use GLM 5.3 or GLM 5.3 Flash?
We classify GLM 5.3 in the frontier tier and GLM 5.3 Flash in the balanced tier. Test whether either meets your accuracy, tool-use and latency requirements before choosing on price.

Next step

Choosing between them

The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.

  • Input price: GLM 5.3 Flash costs $0.15 per 1M tokens versus $1.40 for GLM 5.3 — a 9.3x difference at the headline tier.
  • Context: GLM 5.3 Flash takes 1.05M against 1M for GLM 5.3 — only decisive if your prompts approach the smaller window.
  • Positioning: GLM 5.3 sits in the frontier tier, GLM 5.3 Flash in the balanced tier. Compare accuracy, reliability, latency, and cost on representative tasks before choosing.
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