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Grok 4.20 Reasoning API Pricing: Dedicated Thinking Tokens at Scale

Detailed xAI Grok 4.20 Reasoning API pricing ($2.00/M input, $6.00/M output), dedicated reasoning token budgets, 2M context window, and enterprise token costs.

Full specs, context window and API limits →

How much does Grok-4.20 Reasoning cost per million tokens?

xAI Grok 4.20 Reasoning charges $2.00 per million input tokens and $6.00 per million output tokens ($3.00/M blended at 3:1). Features dedicated reasoning tokens, 2M context, and live data search. Verified 2026-09-08.

Verified 2026-09-07 source
Input
$2.00/M
Output
$6.00/M
Blended
$3.00/M
Provider
Verified 2026-04-06source

How much does Grok-4.20 Reasoning cost per 1,000 requests?

Computed from generated token pricing. Each row assumes the listed input and output tokens per request; this model has no measured verbosity factor, so the unadjusted output estimate is shown.

Request shapeInput tokensOutput tokensCost / 1,000 requests
Short10050$0.5000
Medium1,000500$5.0000
Long4,0002,000$20.0000

Formula: ((input price × input tokens) + (output price × output tokens × verbosity factor)) ÷ 1,000,000 × 1,000. Assumptions: short 100/50, medium 1,000/500, long 4,000/2,000 input/output tokens per request. Unadjusted — no measured verbosity factor is available.

Three model-specific pricing decisions

The reasoning variant uses the same listed token rate as its paired variant in the current registry. Its premium is therefore exposed as output expansion, not invented as a hidden per-token surcharge.

1. Equal-rate audit and reasoning-token expansion

ShapeListed rateReasoning output assumption100K cost
Chat$2.00 in / $6.00 out500 visible output$700.00
Expanded reasoningSame listed rate2× output tokens$1000.00
Heavy reasoningSame listed rate4× output tokens$1600.00

2. Accepted-answer uplift and retry crossover against Grok 4.3

Fixed workload (input / output)Grok-4.20 ReasoningGrok 4.3Decision boundary
Reasoning coding · 4,000 / 1,000$1400.00$750.0015% accepted-result uplift required to justify the higher bill
Long agent · 16,000 / 2,000$4400.00$2500.0020% accepted-result uplift required to justify the higher bill

Formula: 100,000 × (input tokens × input $/M + output tokens × output $/M) ÷ 1,000,000. Uplift is a decision threshold, not a measured quality claim.

3. 1M-context operational-risk table

DimensionDated evidenceCost/decision treatment
Token price$2.00 / $6.00 per MSourced registry input
Latency52 tokens/secDo not convert speed to dollars
Context fit1M context claim unavailable in pricing recordCheck model specification owner
Cache / batchUnavailableNo zero-cost assumption
SLAUnavailableNo SLA claim

Verified 2026-04-06. Luna is the data owner for this server-rendered module. “Unavailable” means no compatible dated evidence was found; it is never treated as zero. First-party price source · Run this exact scenario.

All three decisions are server-rendered for Grok-4.20 Reasoning; fixed inputs, formulas, dated sources, and unavailable states are intentionally visible.

Batch 67 · exact model pricing decision contributions · verified 2026-09-07

Exact model boundary: xAI grok-4.20-0309-reasoning (slug grok-4-20-0309-reasoning). First-party provider pricing and API documentation remain fact owners.

Reasoning token budget and monthly expenditure matrix

Frozen Batch 67 scenario board. Formula / deterministic rule: monthly_spend = calls * ((in_tokens * 2.00 + out_tokens * 6.00) / 1M) Boundary: Owns reasoning token expenditure modeling for Grok 4.20 Reasoning.

Frozen scenario / field IDModel, identity, provider, and evidence fieldsResultState
batch67-grok-4-20-0309-reasoning-m1-r1
5K mathematical proofs
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=5K mathematical proofs; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 5K mathematical proofs is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m1-r2
25K algorithmic coding challenges
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=25K algorithmic coding challenges; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 25K algorithmic coding challenges is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m1-r3
50K architectural design reviews
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=50K architectural design reviews; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 50K architectural design reviews is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m1-r4
prompt caching active (75% read discount)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=prompt caching active (75% read discount); workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — prompt caching active (75% read discount) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m1-r5
batch processing active (50% both)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=batch processing active (50% both); workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — batch processing active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m1-r6
unresolved pricing currency
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=unresolved pricing currency; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — unresolved pricing currency has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: xAI Grok developer pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.

Context window saturation (2M scale) capability gate

Frozen Batch 67 scenario board. Formula / deterministic rule: eligible = (context <= 2M ? Eligible : Excluded); extreme long-context reasoning Boundary: Owns context scaling and capability gating for large inputs.

Frozen scenario / field IDModel, identity, provider, and evidence fieldsResultState
batch67-grok-4-20-0309-reasoning-m2-r1
small library codebase (50K tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=small library codebase (50K tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — small library codebase (50K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m2-r2
medium application service (250K tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=medium application service (250K tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — medium application service (250K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m2-r3
large monolithic codebase (500K tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=large monolithic codebase (500K tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — large monolithic codebase (500K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m2-r4
enterprise monorepo (1M tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=enterprise monorepo (1M tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — enterprise monorepo (1M tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m2-r5
2M full context saturation test
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=2M full context saturation test; context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — 2M full context saturation test is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m2-r6
unsupported archive payload format
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=unsupported archive payload format; context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — unsupported archive payload format has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: xAI Grok documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.

Deliberation budget control and deep mathematical proof accuracy

Frozen Batch 67 scenario board. Formula / deterministic rule: proof_roi = saved_engineering_hours - ((in_tokens * 2.00 + out_tokens * 6.00) / 1M) Boundary: Owns reasoning depth modeling and return-on-investment calculations.

Frozen scenario / field IDModel, identity, provider, and evidence fieldsResultState
batch67-grok-4-20-0309-reasoning-m3-r1
formal mathematical verification
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=formal mathematical verification; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — formal mathematical verification is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m3-r2
cryptographic protocol validation
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=cryptographic protocol validation; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — cryptographic protocol validation is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m3-r3
distributed consensus protocol proof
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=distributed consensus protocol proof; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — distributed consensus protocol proof is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m3-r4
optimizing compiler intermediate representation
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=optimizing compiler intermediate representation; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — optimizing compiler intermediate representation is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch67-grok-4-20-0309-reasoning-m3-r5
reasoning token budget exhaustion
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=reasoning token budget exhaustion; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — reasoning token budget exhaustion has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required
batch67-grok-4-20-0309-reasoning-m3-r6
unresolved proof specification
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=unresolved proof specification; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicitUnavailable — unresolved proof specification has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: xAI Grok documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.

Method and limitations: formulas are deterministic; observed and assumed inputs are labeled; no missing provider, host, account, region, realm, alias, snapshot, revision, weight, artifact, control, tool, modality, workload, rate-period, timestamp, or result is transferred. Run the grok-4-20-0309-reasoning Batch 67 scenario →

Batch 75 Verified Model Pricing IntelligenceModel owner: grok-4-20-0309-reasoning (xAI)Audit date: 2026-09-08

Grok 4.20 Reasoning API Pricing: Dedicated Thinking Tokens at Scale

xAI Grok 4.20 Reasoning charges $2.00 per million input tokens and $6.00 per million output tokens ($3.00/M blended at 3:1). Features dedicated reasoning tokens, 2M context, and live data search. Verified 2026-09-08.

Reasoning token budget and monthly expenditure matrix

Frozen Batch 75 scenario board. Formula / deterministic rule: monthly_spend = calls * ((in_tokens * 2.00 + out_tokens * 6.00) / 1M) Boundary: Owns reasoning token expenditure modeling for Grok 4.20 Reasoning.

Frozen scenario / field IDModel, identity, provider, and evidence fieldsResultState
batch75-grok-4-20-0309-reasoning-m1-r1
5K mathematical proofs
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=5K mathematical proofs; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — 5K mathematical proofs is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m1-r2
25K algorithmic coding challenges
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=25K algorithmic coding challenges; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — 25K algorithmic coding challenges is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m1-r3
50K architectural design reviews
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=50K architectural design reviews; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — 50K architectural design reviews is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m1-r4
prompt caching active (75% read discount)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=prompt caching active (75% read discount); workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — prompt caching active (75% read discount) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m1-r5
batch processing active (50% both)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=batch processing active (50% both); workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — batch processing active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m1-r6
unresolved pricing currency
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=unresolved pricing currency; workload; prompt tokens; completion tokens; standard spend; cached spend; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — unresolved pricing currency has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: xAI Grok developer pricing; verification date 2026-09-08. Missing or conflicting joins fail closed.

Context window saturation (2M scale) capability gate

Frozen Batch 75 scenario board. Formula / deterministic rule: eligible = (context <= 2M ? Eligible : Excluded); extreme long-context reasoning Boundary: Owns context scaling and capability gating for large inputs.

Frozen scenario / field IDModel, identity, provider, and evidence fieldsResultState
batch75-grok-4-20-0309-reasoning-m2-r1
small library codebase (50K tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=small library codebase (50K tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — small library codebase (50K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m2-r2
medium application service (250K tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=medium application service (250K tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — medium application service (250K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m2-r3
large monolithic codebase (500K tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=large monolithic codebase (500K tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — large monolithic codebase (500K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m2-r4
enterprise monorepo (1M tokens)
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=enterprise monorepo (1M tokens); context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — enterprise monorepo (1M tokens) is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m2-r5
2M full context saturation test
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=2M full context saturation test; context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — 2M full context saturation test is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m2-r6
unsupported archive payload format
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=unsupported archive payload format; context size; codebase eligible; prompt cost; completion cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — unsupported archive payload format has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: xAI Grok documentation; verification date 2026-09-08. Missing or conflicting joins fail closed.

Deliberation budget control and deep mathematical proof accuracy

Frozen Batch 75 scenario board. Formula / deterministic rule: proof_roi = saved_engineering_hours - ((in_tokens * 2.00 + out_tokens * 6.00) / 1M) Boundary: Owns reasoning depth modeling and return-on-investment calculations.

Frozen scenario / field IDModel, identity, provider, and evidence fieldsResultState
batch75-grok-4-20-0309-reasoning-m3-r1
formal mathematical verification
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=formal mathematical verification; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — formal mathematical verification is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m3-r2
cryptographic protocol validation
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=cryptographic protocol validation; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — cryptographic protocol validation is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m3-r3
distributed consensus protocol proof
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=distributed consensus protocol proof; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — distributed consensus protocol proof is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m3-r4
optimizing compiler intermediate representation
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=optimizing compiler intermediate representation; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — optimizing compiler intermediate representation is a frozen fixture pending exact identity, configuration, and denominator joins.UNTESTED — assumption cannot establish a verdict
batch75-grok-4-20-0309-reasoning-m3-r5
reasoning token budget exhaustion
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=reasoning token budget exhaustion; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — reasoning token budget exhaustion has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required
batch75-grok-4-20-0309-reasoning-m3-r6
unresolved proof specification
model=grok-4.20-0309-reasoning; slug=grok-4-20-0309-reasoning; provider=xAI; scenario=unresolved proof specification; reasoning problem; thinking depth budget; token cost; net economic ROI; recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicitUnavailable — unresolved proof specification has no matched, dated bilateral observation.FAIL CLOSED — manual, probe, or source evidence required

First-party provenance: xAI Grok documentation; verification date 2026-09-08. Missing or conflicting joins fail closed.

How fast is Grok-4.20 Reasoning?

Tokens / sec
52
TTFT
540 ms
Rank
#27 of 31
$ / M ÷ t/s
$0.06
Measured with 5 runs on a fixed prompt — see the full methodology.

How much does Grok-4.20 Reasoning cost at scale?

Tokens / monthEst. cost (blended 3:1)
100,000$0.30
1,000,000$3.00
10,000,000$30.00
100,000,000$300.00

How does Grok-4.20 Reasoning compare with other models?

Grok-3 Mini$0.26/MGrok 4.3$1.56/MGrok-3$2.50/MGrok-4.20$3.00/MGrok 4.6$3.00/MGrok-4.20$3.00/MGrok 4.6$3.00/MGrok 4.5$3.00/M
See all xAI models →

What is Grok-4.20 Reasoning best for?

#11 for Math & Reasoning#12 for Image Understanding#16 for Long Documents & RAG
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Which Grok-4.20 Reasoning head-to-head comparisons are available?

Grok-4.20 Reasoning vs Claude Opus 4.8Grok-4.20 Reasoning vs Grok 4.3

What are common questions about Grok-4.20 Reasoning?

Is Grok-4.20 Reasoning cheaper than Grok-4.20?

Grok-4.20 Reasoning costs $3.00/M blended tokens, Grok-4.20 costs $3.00/M — Grok-4.20 is cheaper.

How much does 1 million tokens cost with Grok-4.20 Reasoning?

At a 3:1 input:output ratio, 1 million blended tokens costs approximately $3.00. Pure input costs $2.00/M; pure output costs $6.00/M.

What does Grok-4.20 Reasoning cost at high volume?

At 100 million blended tokens a month, Grok-4.20 Reasoning costs approximately $300.00. See the cost-at-scale table below for other volumes.

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