Enter opens the highlighted result. Esc closes.

DeepSeek V4 Flash 0731 vs Grok 4.20

DeepSeek V4 Flash 0731 leads Grok 4.20 on coding, 51.8 to 33.3 on the Vibe Coding Index, and DeepSeek V4 Flash 0731 costs 8.9x less per output token ($0.28 vs $2.50 per million). Updated October 21, 2026; 34 benchmarks have a result for both.

Replace DeepSeek V4 Flash 0731 Replace Grok 4.20
DeepSeek V4 Flash 0731DeepSeek
Coding
51.8
Overall
55.2
Output $/M
$0.28
25
Grok 4.20xAI
Coding
33.3
Overall
41.0
Output $/M
$2.50
9
vs boards won of 34 shared

DeepSeek V4 Flash 0731 or Grok 4.20: which to pick

Pick DeepSeek V4 Flash 0731 for coding: it scores 51.8 on the Vibe Coding Index against 33.3 for Grok 4.20.

Pick Grok 4.20 for a larger context window (2M against 1.05M tokens) and work measured by GPQA Diamond (Artificial Analysis run) or ARC-AGI, where it leads.

Model ADeepSeek V4 Flash 0731DeepSeek51.8/1004 independent benchmarks$0.01 per solved taskModel BGrok 4.20xAI33.3/1002 independent benchmarks$0.72 per solved task
Shared results
34
DeepSeek V4 Flash 0731 only
21
Grok 4.20 only
21
Like-for-like categories
7 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
DeepSeek V4 Flash 0731 51.8 from 4 benchmarks, Grok 4.20 33.3 from 2 benchmarks.
Widest category
Coding, 27.0 points apart on average over 6 shared benchmarks.
Widest single gap
Vibe Code Bench (Vals AI): DeepSeek V4 Flash 0731 74.7% against Grok 4.20 4.1%, 70.7 points apart on a 0 to 100 scale.
Output price
DeepSeek V4 Flash 0731 $0.28 against Grok 4.20 $2.50 per million output tokens, 8.9x apart.
Context window
DeepSeek V4 Flash 0731 takes 1.05M tokens, Grok 4.20 2M.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryDeepSeek V4 Flash 0731BarsGrok 4.20Ties
Coding60
Intelligence20
Agentic work40
Reasoning23
Knowledge14
Web design62
General40
All shared boards259
CodingLike-for-likeSix of these boards feed the Vibe Coding Index60
Coding benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
AA Coding Index69.1Not measuredOnly DeepSeek V4 Flash 0731 measured
LiveCodeBench (Vals AI)87.3%84.3%DeepSeek V4 Flash 0731
SWE-bench Verified (Vals AI)88.8%72.2%DeepSeek V4 Flash 0731
Terminal-Bench 4 (Vals AI)18.7%Not measuredOnly DeepSeek V4 Flash 0731 measured
Vibe Code Bench (Vals AI)74.7%4.1%DeepSeek V4 Flash 0731
Code migration (Vals AI)38.6%0.3%DeepSeek V4 Flash 0731
ProgramBench (Vals AI)0.0%Not measuredOnly DeepSeek V4 Flash 0731 measured
IOI (Vals AI)32.7%Not measuredOnly DeepSeek V4 Flash 0731 measured
Terminal-Bench 2.1 (Vals AI)67.0%44.2%DeepSeek V4 Flash 0731
SkillsBench (Vals AI)50.7%Not measuredOnly DeepSeek V4 Flash 0731 measured
CyberBench (Vals AI)72.1%Not measuredOnly DeepSeek V4 Flash 0731 measured
SciCode50.3%Not measuredOnly DeepSeek V4 Flash 0731 measured
Terminal-Bench Hard (Artificial Analysis run)Not measured37.9%Only Grok 4.20 measured
Terminal-BenchNot measured57.3%Only Grok 4.20 measured
FrontierCode18.8%Not measuredOnly DeepSeek V4 Flash 0731 measured
WeirdML63.0%52.3%DeepSeek V4 Flash 0731
ALE-Bench1306.1Not measuredOnly DeepSeek V4 Flash 0731 measured
Neither model has a result on the other 22 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
AA Intelligence Index34.325.7DeepSeek V4 Flash 0731
Epoch Capabilities Index154.8152.1DeepSeek V4 Flash 0731
Agentic workLike-for-likePublic boards, shown as published, kept out of the index40
Agentic work benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
AA Agentic Index41.0Not measuredOnly DeepSeek V4 Flash 0731 measured
Design Arena: agents building web appsNot measured1144Only Grok 4.20 measured
Design Arena: agents building full-stack appsNot measured1054Only Grok 4.20 measured
Design Arena: agents building mobile appsNot measured1090Only Grok 4.20 measured
Design Arena: agents building Android appsNot measured1052Only Grok 4.20 measured
Design Arena: agents building Godot gamesNot measured1089Only Grok 4.20 measured
Design Arena: HTML slidesNot measured1180Only Grok 4.20 measured
Finance Agent (Vals AI)49.5%28.5%DeepSeek V4 Flash 0731
Tax Agent Bench (Vals AI)28.1%7.0%DeepSeek V4 Flash 0731
Legal Research Bench (Vals AI)30.3%13.9%DeepSeek V4 Flash 0731
Excel Modeling Benchmark (Vals AI)57.0%11.7%DeepSeek V4 Flash 0731
BioMysteryBench (Vals AI)64.4%Not measuredOnly DeepSeek V4 Flash 0731 measured
Terminal-Bench-Science (Vals AI)4.3%Not measuredOnly DeepSeek V4 Flash 0731 measured
τ²-Bench TelecomNot measured93.0%Only Grok 4.20 measured
Vending-Bench 2Not measured$4,663Only Grok 4.20 measured
Neither model has a result on the other 26 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index23
Reasoning benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
GPQA Diamond89.9%88.6%DeepSeek V4 Flash 0731
MMMU Pro (Vals AI)Not measured83.5%Only Grok 4.20 measured
GPQA Diamond (Artificial Analysis run)90.8%91.1%Grok 4.20
Humanity's Last Exam (Artificial Analysis run)38.6%34.5%DeepSeek V4 Flash 0731
GPQA Diamond (Epoch AI run)91.0%Not measuredOnly DeepSeek V4 Flash 0731 measured
ARC-AGI89.0%89.5%Grok 4.20
ARC-AGI-261.4%65.1%Grok 4.20
SimpleBench61.1%Not measuredOnly DeepSeek V4 Flash 0731 measured
Chess puzzles32.0%Not measuredOnly DeepSeek V4 Flash 0731 measured
Mystery game puzzles34.0%Not measuredOnly DeepSeek V4 Flash 0731 measured
Kagi LLM BenchmarkNot measured75.0%Only Grok 4.20 measured
Neither model has a result on the other 11 boards here
MathDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
Math benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
AIMENot measured96.5%Only Grok 4.20 measured
OTIS Mock AIME94.4%Not measuredOnly DeepSeek V4 Flash 0731 measured
FrontierMath, tiers 1 to 357.5%Not measuredOnly DeepSeek V4 Flash 0731 measured
FrontierMath, tier 424.4%Not measuredOnly DeepSeek V4 Flash 0731 measured
ProofBench56.0%Not measuredOnly DeepSeek V4 Flash 0731 measured
Neither model has a result on the other 8 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index14
Knowledge benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
MMLU Pro86.2%86.3%Grok 4.20
LegalBench (Vals AI)77.7%77.7%Grok 4.20
CaseLaw (Vals AI)Not measured54.4%Only Grok 4.20 measured
CorpFin (Vals AI)61.9%63.7%Grok 4.20
TaxEval (Vals AI)70.7%74.1%Grok 4.20
MortgageTax (Vals AI)Not measured45.4%Only Grok 4.20 measured
MedQA (Vals AI)Not measured94.5%Only Grok 4.20 measured
MedCode (Vals AI)41.4%32.2%DeepSeek V4 Flash 0731
SimpleQA Verified33.6%Not measuredOnly DeepSeek V4 Flash 0731 measured
Neither model has a result on the other 9 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index62
Web design benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
Design Arena: websites12381229DeepSeek V4 Flash 0731
Design Arena: UI components12351199DeepSeek V4 Flash 0731
Design Arena: game dev12081192DeepSeek V4 Flash 0731
Design Arena: data viz11801217Grok 4.20
Design Arena: 3D12091193DeepSeek V4 Flash 0731
Design Arena: all code categories12301221DeepSeek V4 Flash 0731
Design Arena: SVG11851164DeepSeek V4 Flash 0731
Design Arena: ASCII art10901174Grok 4.20
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index40
General benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
SAGE (Vals AI)Not measured38.2%Only Grok 4.20 measured
MedScribe (Vals AI)80.4%63.4%DeepSeek V4 Flash 0731
Vals Multimodal IndexNot measured39.1%Only Grok 4.20 measured
IFBenchNot measured81.2%Only Grok 4.20 measured
Long context reasoning (AA-LCR)79.7%69.0%DeepSeek V4 Flash 0731
DTBench90.9%90.1%DeepSeek V4 Flash 0731
LMCA41.7%38.7%DeepSeek V4 Flash 0731
CL-benchNot measured22.2%Only Grok 4.20 measured
CL-bench LifeNot measured11.9%Only Grok 4.20 measured
Neither model has a result on the other 37 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for DeepSeek V4 Flash 0731 and Grok 4.20
BenchmarkDeepSeek V4 Flash 0731Grok 4.20Leader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

DeepSeek V4 Flash 0731$0.0003Fits in one request
Grok 4.20$0.0025Fits in one request

DeepSeek V4 Flash 0731 costs less

Repository review

50K input + 3K output tokens

DeepSeek V4 Flash 0731$0.0078Fits in one request
Grok 4.20$0.070Fits in one request

DeepSeek V4 Flash 0731 costs less

Agent loop

200K input + 10K output tokens

DeepSeek V4 Flash 0731$0.031Fits in one request
Grok 4.20$0.275Fits in one request

DeepSeek V4 Flash 0731 costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of DeepSeek V4 Flash 0731 and Grok 4.20
SpecificationDeepSeek V4 Flash 0731SpaceXAI Grok 4.20
MakerDeepSeekxAI
WeightsOpen weightsNo public weights listed
ReleasedJuly 31, 2026March 31, 2026
Context window1.05M2M
Input $/Mtok$0.14$1.25
Output $/Mtok$0.28$2.50
Coding index51.833.3
Independent measurements behind it42
Cost per solved task$0.01$0.72
SourceOpenRouter listingOpenRouter listing

Questions

Is DeepSeek V4 Flash 0731 better than Grok 4.20 for coding?

Pick DeepSeek V4 Flash 0731 for coding: it scores 51.8 on the Vibe Coding Index against 33.3 for Grok 4.20. Pick Grok 4.20 for a larger context window (2M against 1.05M tokens) and work measured by GPQA Diamond (Artificial Analysis run) or ARC-AGI, where it leads.

Which is cheaper, DeepSeek V4 Flash 0731 or Grok 4.20?

DeepSeek V4 Flash 0731 costs $0.14 per million input tokens and $0.28 per million output tokens; Grok 4.20 costs $1.25 and $2.50. Per solved SWE-bench Verified task, DeepSeek V4 Flash 0731 costs $0.01 and Grok 4.20 $0.72.

Which has the bigger context window, DeepSeek V4 Flash 0731 or Grok 4.20?

Grok 4.20, with 2M tokens against 1.05M.

How many benchmarks is the DeepSeek V4 Flash 0731 vs Grok 4.20 comparison based on?

34 benchmarks have a result for both models as of October 21, 2026. DeepSeek V4 Flash 0731's coding index rests on 4 independent benchmarks and Grok 4.20's on 2. Where only one model has a result, the page says so instead of naming a winner.

Compare next

Embed this comparison on your site

Free under CC BY 4.0, while the source link stays visible. Preview the frame · Terms and other embeds

<iframe src="https://llmbenchmark.ai/embed/compare/deepseek-v4-flash-0731-vs-grok-4-20" title="DeepSeek V4 Flash 0731 vs Grok 4.20, LLMBenchmark.ai" width="100%" height="360" style="border:0;max-width:100%" loading="lazy"></iframe>
<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/deepseek-v4-flash-0731-vs-grok-4-20">LLMBenchmark.ai, DeepSeek V4 Flash 0731 vs Grok 4.20</a></p>