What is the difference between GLM 5.3 Flash and Grok 4 Fast (free)?

GLM 5.3 Flash is developed by Zhipu AI while Grok 4 Fast (free) is developed by xAI. GLM 5.3 Flash has a 1.3M token context window vs Grok 4 Fast (free)'s 2.0M. You can compare their actual outputs across 2 challenges on Rival to see how they differ in practice.

Which is better, GLM 5.3 Flash or Grok 4 Fast (free)?

It depends on your use case. GLM 5.3 Flash and Grok 4 Fast (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 2 challenges so you can judge which fits your needs best.

How much does GLM 5.3 Flash cost compared to Grok 4 Fast (free)?

GLM 5.3 Flash costs $0.15/M input tokens and Grok 4 Fast (free) costs $0/M input tokens. Grok 4 Fast (free) is $0.15/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 Grok 4 Fast (free) on Rival?

This page shows a side-by-side comparison of GLM 5.3 Flash and Grok 4 Fast (free) 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 FlashvsGrok 4 Fast (free)

Grok 4 Fast (free) is cheaper than GLM 5.3 Flash at $0/M vs $0.15/M input tokens.

GLM 5.3 Flash and Grok 4 Fast (free) compared across 2 shared prompts
Spec	GLM 5.3 Flash	Grok 4 Fast (free)
Input price	$0.15/M tokens	Free
Output price	$0.5/M tokens	Free
Context window	1.3M tokens	2.0M tokens
Weights	Open	—
Free API (OpenRouter)	No	No
Released	Aug 2026	Sep 2025

Side by side

Same prompt, both answers

Opening lines from every prompt 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

Grok 4 Fast (free)849 words

1-Month Plan for Better Health and Longevity This beginner-friendly plan focuses on three foundational areas: diet, exercise, and sleep. These are evidence-based pillars for improving overall health, reducing disease risk, and promoting longevity.

Read the full answer

Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

GLM 5.3 Flash205 words

Golden Hour Garlic Butter Pasta A silky, savory pasta that comes together faster than delivery! Ingredients (serves 2): 8 oz spaghetti or any pasta 4 tbsp butter 4 cloves garlic, minced (or 1 tsp garlic powder) ½ cup grated Parmesan cheese ½ cup pasta water (reserved) 1 tsp red pepper flakes Salt Prep time: 5 minutes…

Read the full answer

Grok 4 Fast (free)240 words

Pantry Hero Pasta Primavera This simple, savory one-pot pasta dish transforms basic staples into a flavorful, garlicky tomato sauce that's comforting and ready in under 30 minutes.

Read the full answer

Our Verdict

GLM 5.3 Flash

Grok 4 Fast (free)

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

Too close to call

API pricing

Cost per 1M tokens

GLM 5.3 Flash

Input

$0.15

Output

$0.50

Grok 4 Fast (free)

Input

$0.000

Output

$0.000

Where to run it

30 hosts, cheapest first

GLM 5.3 Flash30 hosts

HostInOutContextUptime

DeepInfrafp4$0.07 in$0.25 out1M99.1% up GMI Cloudfp8$0.07 in$0.25 out1M99.2% up Morph$0.08 in$0.28 out1M100% up InferenceNetfp4$0.09 in$0.28 out1M97.5% up Wafer$0.10 in$0.35 out1M99.7% up OpenInferencefp4$0.10 in$0.50 out1M98.6% up

24 more hosts

Relace$0.11 in$0.36 out1M99.7% up Phalafp8$0.13 in$0.42 out1M99.5% up Novitafp8$0.13 in$0.44 out1M99.4% up StreamLakefp8$0.14 in$0.47 out1M99% up Sail Researchfp8$0.14 in$0.47 out1M99% up AtlasCloudfp8$0.15 in$0.50 out1M99.6% up Basetenfp8$0.15 in$0.50 out1M98.7% up CoreWeavenvfp4$0.15 in$0.50 out1M99.5% up DigitalOcean$0.15 in$0.50 out1M93.7% up Fireworks$0.15 in$0.50 out1M99% up Friendli$0.15 in$0.50 out1M98.7% up Inceptronfp8$0.15 in$0.50 out1M98.2% up io.netfp8$0.15 in$0.50 out262k99.2% up Near AIfp8$0.15 in$0.50 out1M98.9% up Parasailfp8$0.15 in$0.50 out1M98.7% up Rekafp8$0.15 in$0.50 out262k98.9% up SiliconFlowfp8$0.15 in$0.50 out1M99.7% up Together$0.15 in$0.50 out1M99.5% up Venice$0.15 in$0.50 out1M98.8% up Z.aifp8$0.15 in$0.50 out1M96.5% up NextBitfp8$0.18 in$0.60 out1M97.9% up Cloudflare Workers AI$0.30 in$1.00 out1.3M99.8% up Modalfp8$0.45 in$1.50 out1M99.6% up Crusoefp4degraded$0.15 in$0.50 out1M93% up

Grok 4 Fast (free)

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 22 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Same prompt, both answers

Beginner's Longevity Plan

Simple 7-Ingredient Recipe

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 Grok 4 Fast (free)?

Which is better, GLM 5.3 Flash or Grok 4 Fast (free)?

How much does GLM 5.3 Flash cost compared to Grok 4 Fast (free)?

How can I compare GLM 5.3 Flash and Grok 4 Fast (free) on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages

Same prompt, both answers

Beginner's Longevity Plan

Simple 7-Ingredient Recipe

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 Grok 4 Fast (free)?

Which is better, GLM 5.3 Flash or Grok 4 Fast (free)?

How much does GLM 5.3 Flash cost compared to Grok 4 Fast (free)?

How can I compare GLM 5.3 Flash and Grok 4 Fast (free) on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages