Comparisons
GLM 5.3 Flash vs DeepSeek V4.1 Flash
Short answer
- GLM-5.3-Flash wins at DeepSeek's peak rates, and it isn't close: official list is $0.15/$0.50 per 1M (input/output) versus DeepSeek's $0.30/$1.20 — 2× less on input, 2.4× less on output.
- DeepSeek V4.1 Flash only gets competitive off-peak, when everything bills at half price. On a straight 10M-in/2M-out workload it lands at $2.70 versus GLM's $2.50 — close, but still behind.
- Where DeepSeek genuinely wins: input-heavy, cache-friendly jobs run off-peak. Its cache-hit rate ($0.006 peak / $0.003 off-peak) is 5–10× cheaper than Z.ai's official cached-input rate ($0.03; OpenRouter resells it at $0.018, so 3–6× there).
- OpenRouter currently sells GLM-5.3-Flash 40% below Z.ai's official price — $0.09/$0.30 — which widens the gap further. Its DeepSeek price matches official rates exactly, off-peak windows included.
Both GLM-5.3-Flash and DeepSeek V4.1 Flash are the "cheap workhorse" tier of their respective labs — and both sit near the bottom of the per-token price ladder. But the way each prices tokens differs enough that the cheaper model depends entirely on when you call and what your traffic looks like. Here is the current math, checked against official pricing pages on .
List prices, side by side
All figures per 1M tokens, in USD, from the official pricing pages (Z.ai docs, DeepSeek docs) and OpenRouter's live model API.
| Rate | GLM-5.3-Flash (official) | DeepSeek V4.1 Flash (official) |
|---|---|---|
| Input, cache miss | $0.15 | $0.30 peak / $0.15 off-peak |
| Input, cache hit | $0.03 | $0.006 peak / $0.003 off-peak |
| Output | $0.50 | $1.20 peak / $0.60 off-peak |
| Context window | 1M | 1M |
| Max output | 128K | 384K |
DeepSeek's peak hours are 01:00–04:00 and 06:00–10:00 UTC, Monday to Friday. Everything else — evenings, nights, and all weekend — bills at half price. Off-peak rates are exactly half of peak, per DeepSeek's pricing page. (We break down the full schedule in DeepSeek Off-Peak Pricing Explained.)
What OpenRouter actually charges today
OpenRouter's /api/v1/models endpoint (the authoritative feed for its resold rates) shows a split that matters if you route through an aggregator:
| Model | Input / 1M | Output / 1M | Cache read / 1M |
|---|---|---|---|
| z-ai/glm-5.3-flash | $0.09 | $0.30 | $0.018 |
| deepseek/deepseek-v4.1-flash | $0.30 peak, $0.15 off-peak | $1.20 peak, $0.60 off-peak | $0.006 peak, $0.003 off-peak |
Two takeaways: OpenRouter resells GLM-5.3-Flash 40% below Z.ai's official list ($0.09/$0.30 vs $0.15/$0.50), while DeepSeek's OpenRouter price is identical to the official rate — including the off-peak windows, which OpenRouter encodes as scheduled price overrides. There's also a z-ai/glm-5.3-flash:batch variant on OpenRouter at $0.075/$0.25 if your jobs can wait. For a broader sweep of who hosts GLM-5.3-Flash and at what rate, see GLM-5.3-Flash API price across four hosts.
Three realistic workloads, one bill each
Same monthly volume for the first two rows: 10M input tokens, 2M output tokens. Third row is the cache-heavy case — 80% of input tokens hit cache — priced off-peak, where DeepSeek puts its best foot forward.
| Workload | GLM-5.3-Flash (official) | DeepSeek V4.1 Flash |
|---|---|---|
| Straight chat, all peak hours | $2.50 | $5.40 |
| Straight chat, all off-peak | $2.50 | $2.70 |
| 80% cache-hit input + 2M output, off-peak | $1.54 | $1.52 |
The third row deserves a walkthrough, because it's DeepSeek's one clean win. With 8M of the 10M input tokens hitting cache: GLM bills 8M × $0.03 + 2M × $0.15 + 2M × $0.50 = $1.54, while DeepSeek bills 8M × $0.003 + 2M × $0.15 + 2M × $0.60 = $1.52. Run the same workload at DeepSeek's peak rates, though, and DeepSeek jumps to $3.05 — double GLM. DeepSeek's cache-hit rate is the cheapest input token in this comparison by a wide margin, but its output price (even at half price) keeps every output-heavy scenario out of reach. (How DeepSeek's cache billing works, unit by unit: DeepSeek Context Caching Explained.)
Push further into input-dominated territory — say 100M input tokens (80% cache-hit) with just 1M of output, all off-peak — and DeepSeek's design pays off properly: $3.84 versus GLM's $5.90. If your traffic is output-heavy chat during business hours, none of that applies and GLM is roughly half the cost.
Specs that aren't about price
Both are mixture-of-experts models with a 1M context window, but they're not interchangeable:
- GLM-5.3-Flash pairs a 320B-total / 18B-activated MoE with a hybrid sparse-plus-linear attention design (Z.ai says this cuts KV cache 4.44× versus GLM-5.3), native multimodal input, and visual/GUI-agent capabilities out of the box. Max output is capped at 128K.
- DeepSeek V4.1 Flash is DeepSeek's first CED-architecture model, activates 8B parameters on input, supports both thinking and non-thinking modes, and takes up to 384K output tokens — useful when you generate long documents in one call. It also exposes FIM completion (non-thinking mode only).
One more practical difference: DeepSeek's documented concurrency limit on this tier is 2,500 requests; Z.ai doesn't publish an equivalent figure on its pricing page.
Which one, then? If you want a single default: GLM-5.3-Flash via OpenRouter is the cheapest always-on, any-hour option right now. Add DeepSeek V4.1 Flash as a second route when your prompts are cache-friendly or your jobs are schedulable — that's where its pricing design pays out. And watch DeepSeek's off-peak schedule if you serve non-US timezones: "peak" there is 01:00–10:00 UTC weekdays, which is off-peak-friendly for Asian evening traffic.
Prices verified against Z.ai's official pricing page and DeepSeek's Models & Pricing documentation, cross-checked against OpenRouter's public model API on . Both labs reserve the right to adjust prices; DeepSeek's off-peak windows exclude Chinese public holidays.
Sources: Z.ai Pricing, Z.ai GLM-5.3-Flash docs, DeepSeek Models & Pricing, OpenRouter model API