Is DeepSeek Down?

MODEL UPDATE + NEW API (2026-10-17): **DeepSeek-V4.1-Flash-1017** replaces V4.1-Flash on the official web, app and API; the change log says the API calling method and pricing are unchanged (use deepseek-flash). Vendor-reported scores: HLE (no tools) 42.6 (44.0 on the text-only subset), Terminal-Bench 4.0 42.3 (run in the Claude Code harness), Automation-Bench v1.0.6 60.5, Agents' Last Exam 35.4, Apex Bench v1.1 72.1, Chartography (tools) 83.0, BabyVision (tools) 92.5, ZeroBench-main (tools, Pass@5) 51.0; DeepSeek also claims shorter outputs and faster task completion, tuned for DeepSeek Harness 0.2.1-rc.1+, Tencent CodeBuddy and WorkBuddy. Same day, DeepSeek opened its **Search and Fetch APIs** (its in-house search engine) to everyone at **$0.75 per 1,000 calls per endpoint**; Search/Fetch calls made as server-side tools in DeepSeek Harness, Claude Code and Codex are free for DeepSeek API users until **2026-10-31 16:00 UTC**, when billing starts. Weights: huggingface.co/deepseek-ai/DeepSeek-V4.1-Flash-1017 (license: MIT).

DEEPSEEK-V4.1-FLASH LANDS ON A NEW ARCHITECTURE, RETIRES V4-FLASH, CUTS PRICES -- AND THE V4-PRO PHASE-OUT WAS ANNOUNCED THEN REVERSED WITHIN FOUR DAYS (2026-09-10 release, 2026-09-14 reversal; vendor-primary throughout): DeepSeek released **DeepSeek-V4.1-Flash**, 'the smallest model in our new architecture family', a **552B-parameter MoE** on a new **Causal Encoder-Decoder** design with **8B parameters active for input and 16B for output**, with **native visual understanding** built in -- so the separate V4-Flash-Vision-Exp line is gone. DeepSeek's headline engineering claim is KV-cache compression: the cache needs **1/4 the HBM and 1/8 the SSD storage** of the previous generation, which it links directly to agent cost ('cache-hit charges often account for a large share of agent costs'). **Weights on Hugging Face under MIT** (deepseek-ai/DeepSeek-V4.1-Flash, created 2026-09-10) with a technical report. **VENDOR BENCHMARKS (first-party, no third-party replication yet):** GPQA Diamond **90.9**, HLE **36.8** (39.1 text-only), Codeforces **3471**, MathArena Apex 65.6, Terminal-Bench 2.1 **90.6**, Terminal-Bench 3.0 30.0, Terminal-Bench 4.0 31.2, DeepSWE v1.1 **74.2**, NL2Repo 65.4, CyberGym **88.1**, SEC-Bench Pro 62.8, HLE with tools 63.9, Automation-Bench 54.8, Agents' Last Exam 31.8. **Compare to V4-Pro-0813's own GA numbers on this page: Terminal-Bench 2.1 87.9, DeepSWE 62.7, NL2Repo 61.5, CyberGym 83.3, Agents' Last Exam 25.7 -- the cheap model now beats the flagship on every shared row**, which DeepSeek states outright ('benchmark results ahead of flagship models, including DeepSeek-V4-Pro'). **API CHANGES:** set `model=deepseek-flash`. **V4-Flash and V4-Flash-Vision-Exp are retired**; the old names temporarily route to V4.1-Flash and are billed at Flash prices. **PRICING (new rates from 04:00 UTC 2026-09-10, verified on the live rate card):** off-peak **$0.003 cache-hit / $0.15 cache-miss input / $0.60 output** per 1M, peak **$0.006 / $0.30 / $1.20**; peak hours are still 01:00-04:00 and 06:00-10:00 UTC, now stated as **Monday through Friday**. Against the V4-Flash rates it replaces ($0.007 / $0.22 / $0.66 off-peak) that is a **~32% input cut, ~9% output cut and ~57% cache-hit cut** -- the first price reduction since the 8/16 rise, though output is still more than double the pre-August flat $0.28. **THE V4-PRO STORY IS THE ONE TO READ CAREFULLY, BECAUSE THE VENDOR CHANGED ITS MIND IN PUBLIC.** The 9/10 release post says: 'Tests by multiple parties put V4.1-Flash ahead of V4-Pro on performance, cost, speed & total runtime. **We're phasing out V4-Pro.** Starting at 04:00 UTC on Sept 14, 2026, all deepseek-v4-pro requests will route to V4.1-Flash at V4.1-Flash rates. This will continue until V4.1-Pro launches.' **Four days later the change log and the rate-card footnote both say the opposite:** 'In response to user demand, **we have decided to continue providing API services for DeepSeek V4 Pro after September 14, 2026, with the billing method remaining unchanged.** We will provide further notice should there be any changes.' The rate card still lists deepseek-v4-pro (DeepSeek-V4-Pro-0813) at $0.66/$1.98 off-peak and $1.32/$3.96 peak, concurrency 500. **So as of 2026-09-14: V4-Pro is alive, unchanged in price, and has no retirement date; a V4.1-Pro is promised with no date.** Aggregators that reported the 9/14 routing as executed are wrong; the news post itself still carries the superseded wording. **PRACTICAL READ:** for almost any workload V4.1-Flash is now the model to use on the DeepSeek API -- it is cheaper than V4-Pro by 4x on input and 3x on output, has vision, and scores higher on the vendor's own agentic suites. Reasons to stay on V4-Pro are limited to reproducibility of an existing pipeline and the 49B-active-parameter model's world-knowledge edge, which V4.1-Flash's benchmark list does not address. **Partners named at launch:** WorkBuddy (incl. CodeBuddy) and OpenCode. Third-party evaluation pending -- treat every number above as vendor-stated.

DEEPSEEK-V4-FLASH-VISION-EXP -- THE CHEAP TIER GETS EYES, AND A FREE FILES API LANDS WITH IT (2026-08-21, vendor-primary): DeepSeek put **DeepSeek-V4-Flash-Vision-Exp** live on the API Platform, an **experimental** multimodal model that DeepSeek says **matches V4-Flash on text** (agents, reasoning, world knowledge) while adding image input. Call it with `model='deepseek-v4-flash-vision-exp'`. **The billing detail is the one that decides whether this is actually cheap: images are tokenized at up to 384 tokens each and billed at V4-Flash pricing** -- so vision is not a separate premium rate, it is ordinary Flash tokens, which is unusually favourable. Supports **Chat Completions, Messages and Responses**, and mixed text+image input via base64, external URL, or the new Files API. **Files API is live and free to use**: upload an image once and reference it by `file_id` across requests instead of re-uploading. **DeepSeek Harness 0.1.1** shipped the same day with out-of-the-box support. **TREAT THE HEADLINE BENCHMARK CLAIM AS VENDOR-STATED AND UNVERIFIED: DeepSeek says that on multimodal agent benchmarks the model 'makes a major leap over V4-Flash, bringing multimodal agent performance close to Opus-4.8'.** No benchmark table, no named suite, no third-party confirmation -- and 'close to' a competitor's flagship is precisely the sort of claim that needs independent replication before it belongs in a ranking. **Also note the 'Exp' suffix: DeepSeek is labelling this experimental, so it is not a stability guarantee.**

THE PEAK/OFF-PEAK PRICE RISE IS NOW EXECUTED AND LIVE -- CONFIRMED ON THE VENDOR RATE CARD (2026-08-16 16:00 UTC, re-verified 2026-08-17): the change we flagged on 8/13 as scheduled has landed. **DeepSeek's Models & Pricing page no longer shows the old $0.435/$0.87 standing rate at all** -- the peak/off-peak table is now the only rate card published, which is the confirmation that matters. **Live V4-Pro rates per 1M:** off-peak **$0.022 cache-hit / $0.66 cache-miss input / $1.98 output**; peak **$0.044 / $1.32 / $3.96**. **Live V4-Flash rates:** off-peak **$0.007 / $0.22 / $0.66**; peak **$0.014 / $0.44 / $1.32**. **Peak hours, verbatim from the page footnote: 'Peak hours are 01:00 - 04:00 and 06:00 - 10:00 UTC (all other hours are off-peak),'** with 'off-peak rates are half of the peak rates.' That is 7 peak hours in 24. **THE CORRECTION THIS PAGE HAS BEEN MAKING SINCE 8/13 NOW STANDS CONFIRMED AGAINST A LIVE RATE CARD, SO DO NOT LET A LATER SOURCE REVERSE IT:** the 'off-peak is half of peak' wording invites reporting this as a discount scheme, and it is not one. Measured against the $0.435/$0.87 price that was in force until 8/16, **V4-Pro off-peak input is up ~52% and off-peak output up ~128%**; at peak, input roughly triples and output is up ~355%. V4-Flash off-peak output is up ~136% from $0.28. **There is still no hour of the day at which the new pricing beats the old.** The practical consequence for anyone who budgeted DeepSeek as the cheap frontier option: the headline gap to Western frontier models has narrowed sharply, and scheduling work into off-peak windows now only avoids a surcharge on top of an already-raised base -- it does not recover the old price. Concurrency limits published alongside are unchanged at 500 (V4-Pro) and 2500 (V4-Flash)

V4-PRO IS FINALLY GA (2026-08-13, vendor change log) -- AND THE ACCOMPANYING 'PEAK/OFF-PEAK' PRICING IS A PRICE **RISE**, NOT A DISCOUNT. THIS IS THE MOST MISREPORTABLE ITEM ON THIS PAGE, SO READ THE NUMBERS. **(1) The GA itself.** DeepSeek's change log states 'The GA release of DeepSeek-V4-Pro has been rolled out on the APP, Web, and API,' model version **DeepSeek-V4-Pro-0813**, calling convention unchanged (`deepseek-v4-pro`). This closes the watch item open since 7/31, when only V4-Flash graduated and DeepSeek said Pro would 'follow soon.' **Vendor-published GA benchmarks:** HLE (without/with tools) **42.7/60.0**, Terminal Bench 2.1 **87.9**, NL2Repo **61.5**, Cybergym **83.3**, DeepSWE **62.7**, Toolathlon-Verified **74.1**, Agents' Last Exam **25.7**, AutomationBench public **31.8**, plus internal sets DSBench-FullStack **71.1** and DSBench-Hard **67.2**. All first-party. **(2) The pricing change -- effective 16:00 UTC on 2026-08-16.** DeepSeek is moving to peak/off-peak billing with 'off-peak prices set at half the peak-hour prices.' **Peak hours are 01:00-04:00 and 06:00-10:00 UTC**; every other hour is off-peak (so ~7 of 24 hours are peak). New V4-Pro rates per 1M: **off-peak $0.022 cache-hit / $0.66 cache-miss input / $1.98 output**; **peak $0.044 / $1.32 / $3.96**. New V4-Flash rates: **off-peak $0.007 / $0.22 / $0.66**; **peak $0.014 / $0.44 / $1.32**. **NOW COMPARE TO WHAT YOU PAY TODAY:** V4-Pro is currently **$0.435 input / $0.87 output**, and V4-Flash **$0.14 / $0.28**. So **even the cheapest new off-peak rate is above the current standing price** -- V4-Pro off-peak input rises ~52% and output ~128%; at peak, input roughly triples and output rises ~355%. V4-Flash off-peak output rises ~136%. **There is no time of day at which the new pricing is cheaper than the old.** Framing it as a discount scheme (which the 'off-peak is half of peak' wording invites) is wrong; the correct read is a substantial across-the-board increase with a time-of-day surcharge layered on top. **This also supersedes our own long-standing note that the 75%-off V4-Pro rate had become the permanent standing price** -- that was true from 2026-05-26 until this change, and it ends on 8/16. **(3) Other GA changes:** thinking effort is now three levels (**low / high / max**) on both Pro and Flash, and the API 'natively supports the OpenAI Responses API format and is specifically adapted for Codex' with a one-click config script

**[SUPERSEDED 2026-08-13 -- V4-Pro reached GA on that date; see the 2026-08-13 entry above. Kept because it documents that the aggregators calling V4 'GA' in July were wrong at the time.]** V4-FLASH OFFICIAL RELEASE / PUBLIC BETA -- AND V4-PRO IS STILL NOT GA (2026-07-31, vendor changelog; CORRECTS WIDESPREAD AGGREGATOR REPORTING): DeepSeek's own change log states, verbatim: 'The official release of the DeepSeek-V4-Flash API is now in public beta... The DeepSeek-V4-Pro API and the APP/WEB models are unchanged. **The official release of DeepSeek-V4-Pro will follow soon.**' So only FLASH graduated -- aggregators claiming 'DeepSeek V4 went GA in mid/late July' are wrong, and V4-Pro remains Preview. No API change needed: set the model name to `deepseek-v4-flash`. **Vendor-published V4-Flash-0731 benchmarks** (agent-focused, stated as 'far exceeding V4-Pro-Preview'): Terminal Bench 2.1 **82.7**, NL2Repo **54.2**, Cybergym **76.7**, DeepSWE **54.4**, Toolathlon verified **70.3**, Agent Last Exam **25.2**, Automation Bench (public) **25.1**, plus internal sets DSBench-FullStack 68.7 and DSBench-Hard 59.6. Caveats DeepSeek states itself: code-agent numbers were run with the **DeepSeek Harness minimal mode (which it says is still 'to be released soon')** at max effort, topp=0.95, temperature=1.0 -- so they are not straightforwardly reproducible yet, and all figures are first-party. Architecture note: **V4-Flash-0731 keeps the same architecture and size as V4-Flash-Preview and was only re-post-trained.** It also now **natively supports the Responses API format and is specifically adapted for Codex**