Head to head · LLM inference · October 2026 research run

Gemini 4 Carbon vs SWE-2 Flash

Gemini 4 Carbon scores 62.6 (B) on agent readiness against SWE-2 Flash's 36.4 (F), and leads in 5 of 7 scored categories. SWE-2 Flash leads on reliability. Both do llm inference.

Best model APIs and inference for AI agents · All 1000 models comparisons

Which one, for what

Gemini 4 Carbon B

Best for Agents on the hardest long tasks (multi-step debugging, large codebases, open-ended research, security work) that can pay frontier prices and already use the Gemini API.

Ahead on

  • Schema & documentation, 85 against 29
  • Agent ergonomics, 93 against 10
  • Maintenance & community, 83 against 53
  • Transparency & trust, 72 against 64

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

Paid tier only, with no free tier to try it on

SWE-2 Flash F

Best for People already using Devin Desktop or Devin CLI who want a cheaper, faster model for routine coding work such as automations, reviews and small changes, while it is free in November 2026.

Ahead on

  • Reliability, 50 against 40

Watch for

No model API, OpenAPI entry or model card. The Devin API's session agents list SWE-2 but not SWE-2 Flash

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Agent ergonomics Gemini 4 Carbon +83

Gemini 4 Carbon 93

Model reading for gemini-4-carbon on the Gemini API. Platform facts are the Gemini API listing's (gemini-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Function calling, with forced calls by FunctionCallingConfig on the API (20). Structured output (13 of 15). Implicit caching with durable caching on by default, cached input 95% off, explicit caches not supported, per the Cloud guide read on 10 November (15). 1,048,576 tokens shared between input and output (15). Batch at half price on the platform (10). Python and JavaScript SDKs (10). Error codes with backoff guidance (10 of 15). 20 + 13 + 15 + 15 + 10 + 10 + 10 = 93.

SWE-2 Flash 10

Model reading (tool use, structured output, caching, context, batch, SDKs). Tool use is Devin's harness, not something a caller configures; no context length, output limit or cache price is published for SWE-2 Flash (5 of 25). No documented output-size or reasoning controls for this model; SWE-2's effort levels aren't stated for Flash (0 of 20). No model-level error documentation (0 of 20). No idempotency or retry guidance (0 of 20). One flag or picker selects it and devin -p runs a single turn and prints to stdout, but there is no SDK or direct endpoint (5 of 15). 5 + 0 + 0 + 0 + 5 = 10.

Schema & documentation Gemini 4 Carbon +56

Gemini 4 Carbon 85

Model reading for gemini-4-carbon on the Gemini API. Platform facts are the Gemini API listing's (gemini-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Discovery document for GenerateContent (20 of 25). llms.txt with Markdown twins (10). The Cloud developer guide says what Carbon takes and refuses, the parameters that return 400 or are ignored, and how to migrate (15 of 20). Structured output to a JSON Schema with some keywords not enforced (10 of 15). Examples and an errors page (15). Dated changelog and model versions (15). 20 + 10 + 15 + 10 + 15 + 15 = 85.

SWE-2 Flash 29

Model reading. No model API, so no OpenAPI entry; the Devin v3 OpenAPI file lists SWE-2 agents only, and no model card was found (0). docs.devin.ai serves llms.txt and Markdown copies of every page (10). The launch post says what it is for (automations, code review, feature development, documentation) and the CLI docs say when to pick a SWE model, but the models pages don't list SWE-2 Flash yet (6 of 20). No documented model ID, reasoning settings, context or output limits to type (0 of 15). The CLI pages show --model and /model examples, with no model-specific errors (3 of 15). Named, dated model versions on Cognition's blog and public release notes, but no release note for SWE-2 Flash yet; the newest is 2 November (10 of 15). 0 + 10 + 6 + 0 + 3 + 10 = 29.

Maintenance & community Gemini 4 Carbon +30

Gemini 4 Carbon 83

Model reading for gemini-4-carbon on the Gemini API. Platform facts are the Gemini API listing's (gemini-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Released to developers on 10 November 2026, with the platform's changelog (30). Deprecations with earliest dates and no stated minimum notice (4 of 12). Shutdowns in the last 90 days kept to their table (4 of 8). Dated changelog (15). SDK replies not sampled (5 of 10). Current SDKs (15). Runtimes stated (10). 30 + 4 + 4 + 15 + 5 + 15 + 10 = 83.

SWE-2 Flash 53

Model reading. Released 4 November 2026 (30). Churn and notice in place of release counts: SWE-1.6, SWE-1.7, SWE-1.7 Lightning, SWE-2 (10 September) and now SWE-2 Flash in a few months, with no model deprecation notice period found and short names that move to the newest model (10 of 20). Public release notes and a support address, no public tracker (10 of 25). No official SDK for the model (0 of 15). The docs are kept current but don't yet cover this model (3 of 10). 30 + 10 + 10 + 0 + 3 = 53.

Reliability SWE-2 Flash +10

Gemini 4 Carbon 40

Model reading for gemini-4-carbon on the Gemini API. Platform facts are the Gemini API listing's (gemini-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Status page at aistudio.google.com/status with no readable components or history (10 of 20) and no readable incident record (5 of 30). Rate-limit tiers and spend limits published, per-model limits in AI Studio (5 of 15). Backoff guidance for 429 and 503 and SDK retries (15). No SLA (0). Carbon's launch stage isn't stated in Google's developer post, the Antigravity post or the Cloud developer guide read on 10 November, and the model ID carries no preview label, so half (5 of 10, a judgement call; Argon's GA earned the platform 10). 10 + 5 + 5 + 15 + 0 + 5 = 40.

SWE-2 Flash 50

Model reading, for the surface it runs on, Devin Desktop and Devin CLI. Status page at www.devinstatus.com (Atlassian Statuspage) with Desktop Agent and Desktop Tab components besides the cloud ones, read on 4 November 2026 (20). The history feed for the 90 days from 6 August lists 'Devin unavailable' for 20 minutes on 13 August with no component named, read as across the board and a major as on the devin listing; Devin Cloud unavailable on 13 August and the web app down on 24 September name cloud surfaces this model doesn't use; the rest are degraded-performance incidents (new sessions on 3 September, 'multiple services' on 17 September, Ask Devin on 26 October, automation triggers on 4 November) and session queuing on 10 and 11 August, read as minor and a scheduled Devin Desktop extension marketplace upgrade on 7 August, read as maintenance. One major (10). No rate limit figures for the model or the CLI; usage is a daily and weekly quota with no numbers (0). No 429, backoff or retry guidance for this surface (0). Cognition publishes an SLA (25 February 2026) with uptime and response times that applies when included in an order form, read as a contractual SLA on Enterprise, as on other listings (10). The launch post makes it available today with no preview or beta label (10). 20 + 10 + 0 + 0 + 10 + 10 = 50.

Transparency & trust Gemini 4 Carbon +8

Gemini 4 Carbon 72

Model reading for gemini-4-carbon on the Gemini API. Platform facts are the Gemini API listing's (gemini-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Closed service with clear terms, SDKs Apache-2.0 (15). Paid-tier data isn't used, abuse retention has no number, and request storage is on by default for new paid projects (20 of 30). Deprecations table (15 of 20). Data may be cached anywhere Google has facilities; no subprocessor list checked (5 of 20). Every benchmark figure is Google's own. 15 + 20 + 15 + 5 = 55.

SWE-2 Flash 64

Editorial half. Closed model under Cognition's platform terms; the weights aren't public and the sharing programme isn't described yet (15). Terms, privacy policy, security page and DPA agree, with training on self-serve data by default and no retention periods, as read for the devin listing (18). The API versioning policy covers API endpoints, not models, and no model deprecation notice was found (5 of 20). Sub-processors listed with purpose and country, per the devin listing's 8 October check (18). 15 + 18 + 5 + 18 = 56.

Score by category

CategoryWeight this runGemini 4 CarbonSWE-2 FlashEdge
Reliability16%204050SWE-2 Flash +10
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28529Gemini 4 Carbon +56
Agent ergonomics13%16.29310Gemini 4 Carbon +83
Security & auth14%17.55553Gemini 4 Carbon +2
Payments & pricing10%12.52020even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88353Gemini 4 Carbon +30
Transparency & trust7%8.87264Gemini 4 Carbon +8
Negative events≤150-2
TotalB 62.6/100F 36.4/100

Facts side by side

FactGemini 4 CarbonSWE-2 Flash
KindModel APIModel API
VendorGoogleCognition AI, Inc.
Hosted endpointhttps://generativelanguage.googleapis.com/v1betano (local only)
Transports
AuthAPI keyOAuth or key
PricingPay per useFreemium
x402nono
LicenceClosed model, used through the Gemini API and Google's apps under Google's termsProprietary model, used through Devin Desktop and Devin CLI under Cognition's Platform Terms of Service. The weights are not public; Cognition says it is building a programme to share them with industry partners and researchers
Read-only variant documentednono
llms.txtyesyes
Last release2026-11-102026-11-04
Terms last updated2026-04-282026-06-30
Privacy policy last updated2026-10-012026-03-09
Customer content may train modelsyesyes, with an opt-out
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingyesyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textyes

Verdicts

Gemini 4 Carbon

Google's strongest model on the same Gemini API as Argon, with a 1M-token budget, function calling and structured output, at an introductory $2 and $10 per million tokens. Paid tier only, sampling parameters are ignored or refused, its launch stage isn't stated, and the price rises to $4 and $20 at a date Google hasn't given.

SWE-2 Flash

A new small coding model from Cognition that anyone can try free in Devin Desktop and Devin CLI until 30 November 2026, with strong vendor-reported coding scores. It has no model API, no published per-token price, context length or model card, and no public weights, so an agent can reach it only by driving Devin's own CLI.

Before you call either

Gemini 4 Carbon

  1. Call generateContent at https://generativelanguage.googleapis.com/v1beta with model gemini-4-carbon and an x-goog-api-key on a billed project
  2. Set thinking_level (LOW, MEDIUM or HIGH) instead of thinking_budget, and don't send temperature, top_p or top_k
  3. Count output against the same 1,048,576-token limit as the input, and set max_output_tokens for long answers
  4. Put static prompt content first so implicit caching applies; explicit caches aren't supported
  5. Use gemini-4-argon for most coding and knowledge work, and Carbon for the hardest long tasks, as Google suggests

SWE-2 Flash

  1. There is no endpoint to call. Run Devin CLI single-turn with devin -p and pick the model with --model; the SWE-2 Flash model ID isn't documented yet, so check /model in the CLI first
  2. Don't rely on the short name swe. The docs say it resolves to the latest model in the family, which may be SWE-2 rather than SWE-2 Flash
  3. Plan for billing to start on 1 December 2026. The free period covers Devin Desktop and CLI only, not Devin cloud sessions
  4. Treat Cognition's benchmark figures as the vendor's. No independent result for SWE-2 Flash was found
  5. Keep credentials.toml private. The token in it doesn't expire by default and carries the signed-in user's access

Questions

Which is better for AI agents, Gemini 4 Carbon or SWE-2 Flash?

Gemini 4 Carbon scores 62.6 (B) on agent readiness against SWE-2 Flash's 36.4 (F), and leads in 5 of 7 scored categories. SWE-2 Flash leads on reliability.

Do Gemini 4 Carbon and SWE-2 Flash need an API key?

Gemini 4 Carbon needs an API key. SWE-2 Flash takes an API key or an OAuth sign-in.

Can an agent call Gemini 4 Carbon and SWE-2 Flash without installing anything?

Gemini 4 Carbon has a hosted endpoint at https://generativelanguage.googleapis.com/v1beta. No hosted endpoint is listed for SWE-2 Flash.

Other comparisons with Gemini 4 Carbon or SWE-2 Flash

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.