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Model comparison

Gemini 3.5 Flash vs GLM 5.3 Flash

Google against Z.ai, compared on context, price, and verified benchmark results.

Catalog record checked September 3, 2026Individual provider fields may changeEvidence confidence: High — see receipts below

Google

Gemini 3.5 Flash

Balanced

vs

Z.ai

GLM 5.3 Flash

Balanced · Open weights

AI model capability comparison
SpecificationGemini 3.5 FlashGLM 5.3 Flash
ProviderGoogleZ.ai
TierBalancedBalanced
Context window1MWinner: 1.05M
Max output64KWinner: 131K
Input / 1M tokens$1.50Winner: $0.15
Output / 1M tokens$9Winner: $0.50
WeightsClosedOpen
ParametersNot disclosedUnverified320B total / 18B active (MoE)
Reasoning levelslow, medium, highNot verifiedUnverified
Modalitiestext, image, video, audio, pdftext, image, video
LicenseNot disclosedUnverifiedMIT
API model idgemini-3.5-flashNot publishedUnverified
ReleasedMay 19, 2026August 26, 2026
Artificial Analysis Intelligence Index (2026-08-14)53Winner: 57
SWE-bench Verified (2026-09-01)Not verifiedUnverified92
Terminal-Bench 2.1 (2026-08)Not verifiedUnverified84.3
DeepSWE 1.1 (2026-08)Not verifiedUnverified63.4
Humanity's Last Exam (2026-08)Not verifiedUnverified55.3

Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

  • 2026-09-01: vals.ai SWE-bench Verified leaderboard (independent, mini-swe-agent bash-only); not published by Z.aiReal GitHub issue resolution: does the model's patch pass the hidden tests. Comparability: comparable with caveat — Post-audit vendor claims and pre-audit scores sit on different task trust levels; scaffolding (agent harness, compute budget) also dominates results. Never aggregate across scaffolds.
  • 2026-08-26: Artificial AnalysisComposite index blending reasoning, knowledge, and coding evals into one 0–100 score. Comparability: directly comparable — AA occasionally rebaselines the index scale between snapshots — a score captured on one date is only comparable to same-snapshot scores (check measuredAt).
  • 2026-08: Z.ai GLM-5.3-Flash blog (vendor, mini-swe-agent, 400K context)Agentic software engineering: pass@1 on real repo tasks with reported cost per completed task. Comparability: directly comparable
  • 2026-08: GLM-5.3-Flash HF model card (vendor, with tools, full set)Agentic terminal work: multi-step tasks executed in a sandboxed shell environment. Comparability: comparable with caveat — Scores across Terminal-Bench major versions (v1 vs v2) are NOT comparable; harness configuration (container, time limits) also shifts results.

Pricing tiers: Gemini 3.5 Flash: $1.50/$9.00 per MTok (single aggregator source — verify before publishing). Multimodal input. · GLM 5.3 Flash: $0.15/$0.50 per MTok is the standard first-party and third-party rate (Z.ai docs; GMI, Novita, Together). A 50% promo tier runs $0.075/$0.25 — confirm which rate your account quotes.

BalancedRecord checked September 2, 2026

Gemini 3.5 Flash

Gemini 3.5 Flash is Google's agent-focused Flash tier launched at Google I/O 2026.

Best for

  • Agentic workflows
  • Multimodal input
  • High-volume work

Watch out

Price is single-source; confirm on Google Cloud before relying on it.

BalancedOpen weightsRecord checked September 3, 2026

GLM 5.3 Flash

GLM 5.3 Flash is Z.ai's natively multimodal open-weight workhorse — 1M context, hybrid sparse/linear attention, near-flagship Intelligence Index at a fraction of the cost.

Best for

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

Watch out

Self-hosting needs ~186GB GPU memory at 4-bit (multi-GPU). Third-party hosts charge more than Z.ai's own API.

When the cheaper one wins

GLM 5.3 Flash is cheaper on output at $0.50 per million tokens against $9 for Gemini 3.5 Flash — about 18×. 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. These are standard-tier API rates, excluding batch and cache discounts.

Run the model picker

Evidence confidence: High

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.
  • 3/5 core specs verified on both sides — Not published for at least one side: parameter count, reasoning levels.
  • 1 shared named benchmark with differing scores — Measured on: Artificial Analysis Intelligence Index.
  • Verified within the last 90 days — Newest catalog check was 8 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? Gemini 3.5 Flash · GLM 5.3 Flash

Common questions

Gemini 3.5 Flash vs GLM 5.3 Flash

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

Is Gemini 3.5 Flash or GLM 5.3 Flash cheaper for input?

GLM 5.3 Flash is cheaper at $0.15 per million input tokens, against $1.50 for Gemini 3.5 Flash — roughly 10× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Gemini 3.5 Flash has tiered pricing: $1.50/$9.00 per MTok (single aggregator source — verify before publishing). Multimodal input. GLM 5.3 Flash has tiered pricing: $0.15/$0.50 per MTok is the standard first-party and third-party rate (Z.ai docs; GMI, Novita, Together). A 50% promo tier runs $0.075/$0.25 — confirm which rate your account quotes.

Is Gemini 3.5 Flash or GLM 5.3 Flash cheaper for output?

GLM 5.3 Flash is cheaper at $0.50 per million output tokens, against $9 for Gemini 3.5 Flash — roughly 18× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Gemini 3.5 Flash has tiered pricing: $1.50/$9.00 per MTok (single aggregator source — verify before publishing). Multimodal input. GLM 5.3 Flash has tiered pricing: $0.15/$0.50 per MTok is the standard first-party and third-party rate (Z.ai docs; GMI, Novita, Together). A 50% promo tier runs $0.075/$0.25 — confirm which rate your account quotes.

Which has the larger context window, Gemini 3.5 Flash or GLM 5.3 Flash?

GLM 5.3 Flash accepts 1.05M tokens against 1M for Gemini 3.5 Flash. This only matters if you routinely send very long documents or large codebases.

Should I use Gemini 3.5 Flash or GLM 5.3 Flash?

Both sit in the balanced tier, so the choice usually comes down to price and context rather than capability. Gemini 3.5 Flash suits agentic workflows; GLM 5.3 Flash suits cost-efficient long-context.

Can I self-host Gemini 3.5 Flash or GLM 5.3 Flash?

GLM 5.3 Flash publishes open weights, but self-hosting and third-party provider access depend on the licence, hardware, serving support, and availability. Gemini 3.5 Flash is a closed model whose supported access paths are controlled by its provider.

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 $1.50 for Gemini 3.5 Flash — a 10x difference at the headline tier.
  • Context: GLM 5.3 Flash takes 1.05M against 1M for Gemini 3.5 Flash — only decisive if your prompts approach the smaller window.
  • Measured capability: GLM 5.3 Flash leads Artificial Analysis Intelligence Index 57 to 53 (measured 2026-08-14).
  • Deployment: GLM 5.3 Flash publishes weights you can self-host; the other is API-only.
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