What is the difference between GLM 5.3 Flash and GPT-5.2 Pro?

GLM 5.3 Flash is developed by Zhipu AI while GPT-5.2 Pro is developed by OpenAI. GLM 5.3 Flash has a 1.3M token context window vs GPT-5.2 Pro's 400K. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

Which is better, GLM 5.3 Flash or GPT-5.2 Pro?

It depends on your use case. GLM 5.3 Flash and GPT-5.2 Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

How much does GLM 5.3 Flash cost compared to GPT-5.2 Pro?

GLM 5.3 Flash costs $0.15/M input tokens and GPT-5.2 Pro costs $21/M input tokens. GLM 5.3 Flash is $20.85/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare GLM 5.3 Flash and GPT-5.2 Pro on Rival?

This page shows a side-by-side comparison of GLM 5.3 Flash and GPT-5.2 Pro across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Updated Aug 2026

GLM 5.3 FlashvsGPT-5.2 Pro

GLM 5.3 Flash is cheaper than GPT-5.2 Pro at $0.15/M vs $21/M input tokens.

GLM 5.3 Flash and GPT-5.2 Pro compared across 12 shared prompts
Spec	GLM 5.3 Flash	GPT-5.2 Pro
Input price	$0.15/M tokens	$21/M tokens
Output price	$0.5/M tokens	$168/M tokens
Context window	1.3M tokens	400K tokens
Weights	Open	Closed
Free API (OpenRouter)	No	No
Released	Aug 2026	Dec 2025

Side by side

Same prompt, both answers

Opening lines from 2 of the 12 prompts both answered. Formatting stripped, words untouched.

Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

GLM 5.3 Flash327 words

1-Month Beginner Health & Longevity Plan 🥗 Area 1: Diet — "Add Before You Subtract" Week 1: Add one vegetable or fruit to every meal. Don't cut anything yet—just add. Week 2: Swap one sugary drink per day for water or unsweetened tea.

Read the full answer

GPT-5.2 Pro837 words

A simple, actionable 1‑month plan (3 pillars: Nutrition, Movement, Sleep/Recovery) Goal for the month: build repeatable “default” habits (not perfection). Time required: ~45–75 min/day total (mostly walking + sleep routine).

Read the full answer

Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

GLM 5.3 Flash518 words

HarborTech Services — 5-Year LBO Summary Entry Math EV = 12.0x × $120m = $1,440.0m; Fees (2%) = $28.8m; Total uses = $1,468.8m Debt: TL = 4.0x × 120 = $480.0m; Mezz = 1.5x × 120 = $180.0m; Total = $660.0m (5.5x) Sponsor equity = $808.8m Base Case Projection ($m) FY26 FY27 FY28 FY29 FY30 Revenue 972.0 1,039.7 1,102.1…

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GPT-5.2 Pro161 words

Entry (close end of FY2025) FY2025 EBITDA = $120.0m Entry EV = 12.0x = 12.0 × 120.0 = $1,440.0m Transaction fees = 2.0% EV = 0.02 × 1,440.0 = $28.8m (equity-funded) Debt at close (5.5x EBITDA = 5.5 × 120 = $660m): Term Loan = 4.0x = $480.0m Mezzanine = 1.5x = $180.0m Equity check Uses = 1,440.0 + 28.8 = $1,468.8m…

Read the full answer

Our Verdict

GLM 5.3 Flash

GPT-5.2 Pro

Not enough votes to call it. On the specs, nothing separates them.

GLM 5.3 Flash costs 336x less per token.

Too close to call

API pricing

Cost per 1M tokens

GLM 5.3 Flash

Input

$0.15

140× cheaper

Output

$0.50

336× cheaper

GPT-5.2 Pro

Input

$21.00

Output

$168.00

GLM 5.3 Flash is cheaper on both: 140× input, 336× output.

Where to run it

30 hosts, cheapest first

GLM 5.3 Flash29 hosts

HostInOutContextUptime

DeepInfrafp4$0.07 in$0.25 out1M99% up InferenceNetfp4$0.09 in$0.28 out1M97.8% up GMI Cloudfp8$0.09 in$0.30 out1M99.2% up Wafer$0.10 in$0.35 out1M99.8% up Relace$0.10 in$0.36 out1M99.9% up OpenInferencefp4$0.10 in$0.50 out1M99.2% up

23 more hosts

GPT-5.2 Pro1 host

HostInOutContextUptime

OpenAI$21.00 in$168.00 out400k100% up

Per million tokens. Prices and uptime via OpenRouter, checked 23 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Same prompt, both answers

Beginner's Longevity Plan

Mini LBO Underwrite

Cost per 1M tokens

30 hosts, cheapest first

What we learned reading every model

Common questions

What is the difference between GLM 5.3 Flash and GPT-5.2 Pro?

Which is better, GLM 5.3 Flash or GPT-5.2 Pro?

How much does GLM 5.3 Flash cost compared to GPT-5.2 Pro?

How can I compare GLM 5.3 Flash and GPT-5.2 Pro on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages

Same prompt, both answers

Beginner's Longevity Plan

Mini LBO Underwrite

Cost per 1M tokens

30 hosts, cheapest first

What we learned reading every model

Common questions

What is the difference between GLM 5.3 Flash and GPT-5.2 Pro?

Which is better, GLM 5.3 Flash or GPT-5.2 Pro?

How much does GLM 5.3 Flash cost compared to GPT-5.2 Pro?

How can I compare GLM 5.3 Flash and GPT-5.2 Pro on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages