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Step 5 Preview vs DeepSeek V4.1 Flash
DeepSeek V4.1 Flash scores higher than Step 5 Preview on all 4 public leaderboards that rate both. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, Step 5 Preview is at 29.5 and DeepSeek V4.1 Flash at 58.7 (out of 100).
Scores as published by each board; table composed November 13, 2026.
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Leaderboard by leaderboard
| Board | Step 5 Preview | DeepSeek V4.1 Flash | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,572.5 | 1,663.7 | DeepSeek V4.1 Flash |
| LiveBench global average (0-100) | 54.9 | 70.3 | DeepSeek V4.1 Flash |
| Vals AI Vals Index accuracy % · weighted finance + coding tasks | 54.8 | 61.3 | DeepSeek V4.1 Flash |
| Artificial Analysis intelligence index · measured runs only | 28.5 | 32.6 | DeepSeek V4.1 Flash |
Raw scores are each board's own scale, so compare within a row, not across rows. Full table: the bench index.
For coding
On the ArtificialWatch coding index, Step 5 Preview is at 26 (#40 of 48) and DeepSeek V4.1 Flash at 70.4 (#13). DeepSeek V4.1 Flash scores higher on all 3 coding boards that rate both.
| Coding board | Step 5 Preview | DeepSeek V4.1 Flash |
|---|---|---|
| LMArena · Coding | 1,481.7 | 1,503.8 |
| LiveBench · Coding | 67.6 | 80.4 |
| Vals Vibe Code Bench | 70.4 | 87.7 |
Step 5 Preview at a glance
- Developer
- StepFun
- Status
- Live since September 20, 2026
Live — Sep 20 · 600B total / ~27B active MoE · 1M ctx · $1.00/$2.70 per 1M, $0.05 cached input · open weights landed Oct 15, as scheduled: FP8 and BF16 checkpoints on Hugging Face and ModelScope, plus an NVFP4 build on Hugging Face (604.3B parameters in the safetensors index; about 650 GB in FP8, 1.2 TB in BF16), under the StepFun Model License 1.0, which adds a 'Powered by StepFun AI' credit past 100M monthly users or $20M monthly revenue and a separate commercial license for device makers and for model-as-a-service firms over $20M a year (license read Oct 15) · aimed at long-horizon agentic work.
StepFun opens Step 5 Preview's weights: 600B total, 27B active, 1M context, under its own license
2026-10-15 · StepFun released the weights of Step 5 Preview on October 15, the date it set when the model went on sale through its API on September 20. FP8 and BF16 checkpoints are on Hugging Face and ModelScope, and an NVFP4 build is on Hugging Face too.
DeepSeek V4.1 Flash at a glance
- Developer
- DeepSeek
- Status
- Live since September 10, 2026
Live — Sep 10 · 1M ctx · $0.15/$0.60 per 1M as our sweep read it, which is DeepSeek's off-peak rate (peak hours on weekdays cost double, $0.30/$1.20, per its pricing page) · DeepSeek serves it under the unversioned id deepseek-flash, so the id itself never carries the version · Oct 17: upgraded in place to the 1017 checkpoint (DeepSeek-V4.1-Flash-1017, per DeepSeek's changelog), same deepseek-flash id and price, web and app updated too; open weights on Hugging Face as deepseek-ai/DeepSeek-V4.1-Flash-1017 (MIT, same config.json as the Sep 10 weights); OpenRouter lists it as deepseek/deepseek-v4.1-flash-1017 at $0.15/$0.60, 1M ctx, 384K max output · Oct 19: the Vals Index (updated Oct 18) scores the 1017 build 56.58%, #14 of 50 and the top open-weight model there, up from 51.32% for the Sep 10 build; $0.64 per test on Vals' run, against $0.33 for the Sep 10 build · Oct 19: DHS ordered DeepSeek products, and third-party products built on DeepSeek, excluded from and removed from US federal civilian agencies (Federal Register 2026-21447, publishing Oct 20) · Oct 20: DeepSeek open-sourced DeepInfer (Apache-2.0), the inference engine it serves V4.1 Flash with, for NVIDIA SM100 GPUs and Huawei Ascend 950 NPUs · Oct 20: Vals says the 1017 build completed 16.3 of 21 objectives on its coming offensive-cybersecurity benchmark, against 15.7 for GPT-6 Sol, on several times the tokens (a first finding; the full evaluation is due in the coming weeks).
DeepSeek open-sources DeepInfer, the engine behind V4.1 Flash, built for NVIDIA Blackwell and Huawei Ascend 950
2026-10-20 · DeepSeek released DeepInfer, the inference framework it says serves DeepSeek-V4.1-Flash at scale, as open source on October 20 under the Apache 2.0 license.
Vals: DeepSeek V4.1 Flash beat GPT-6 Sol on its offensive cybersecurity task, using about five times the tokens
2026-10-20 · Vals AI says DeepSeek V4.1 Flash 1017, an open-weight model, completed more objectives than OpenAI's GPT-6 Sol on a multi-step offensive cybersecurity task built on simulated corporate networks.
Step 5 Preview vs DeepSeek V4.1 Flash: quick answers
Which is better, Step 5 Preview or DeepSeek V4.1 Flash?
It depends on what you measure. DeepSeek V4.1 Flash scores higher than Step 5 Preview on all 4 public leaderboards that rate both. DeepSeek V4.1 Flash's widest lead is on LiveBench. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, Step 5 Preview is at 29.5 and DeepSeek V4.1 Flash at 58.7 (out of 100).
Which is newer, Step 5 Preview or DeepSeek V4.1 Flash?
Step 5 Preview. It went live on September 20, 2026, 10 days after DeepSeek V4.1 Flash (September 10, 2026).
How do Step 5 Preview and DeepSeek V4.1 Flash compare for coding?
On the ArtificialWatch coding index, Step 5 Preview is at 26 (#40 of 48) and DeepSeek V4.1 Flash at 70.4 (#13). DeepSeek V4.1 Flash scores higher on all 3 coding boards that rate both.
Who makes Step 5 Preview and DeepSeek V4.1 Flash?
Step 5 Preview is from StepFun; DeepSeek V4.1 Flash is from DeepSeek.
Where do these numbers come from?
Each score is the leaderboard's own published figure, read by ArtificialWatch (table composed November 13, 2026). Boards measure different things, so raw scores are only comparable within a row.
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