AI Email & Text Classifier Cost — 50k Items/Day
Classifying 1.5M items per month (50k/day) runs $20–$180 — classification is the cheapest LLM workload because outputs are tiny.
Scenario
An ops tool auto-categorizes 50,000 emails, support tickets, or social posts per day across ~20 labels (e.g., "billing", "bug report", "feature request"). Each item is ~400 input tokens; the model returns a 10-20 token label or short JSON. The instruction prompt (~300 tokens with examples) repeats every request, giving high cache value.
| Assumption | Value |
|---|---|
| Items / day | 50,000 |
| Days / month | 30 |
| Input / item | ~400 tokens (300 instruction + 100 item) |
| Output / item | ~15 tokens (label) |
| Cache hit | 60% (instruction repeats) |
Use batch API for non-realtime classification (50% off). With caching + batch, costs can drop another 50% beyond what is shown below.
Monthly cost across recommended models
Calculated at 600M input tokens + 22.5M output tokens, with 60% prompt cache hit rate.
| Model | Input cost | Output cost | Cache savings | Total / mo |
|---|---|---|---|---|
| Deepseek Chat Cheapest | $168 | $9.45 | −$90.72 | $86.73 |
| Gpt 5 Mini | $150 | $45.00 | −$81.00 | $114 |
| Gemini 2.5 Flash | $180 | $56.25 | −$97.20 | $139 |
| Claude Haiku 4 5 | $600 | $113 | −$324 | $389 |
💡 Switching from Claude Haiku 4 5 to Deepseek Chat saves $302/month (78% reduction).
Why these models
Classification is a Haiku/Mini-tier problem — frontier models are wasted here. The discriminating factor is structured output reliability: GPT-5 Mini and Claude Haiku 4.5 lead on JSON schema adherence. DeepSeek is cheapest but you may need retry logic for malformed outputs.
Key insights
- 1. Use JSON response schema (enforced output format) on every request — eliminates retry costs from bad parses.
- 2. For 20+ labels, few-shot examples in the prompt outperform fine-tuning until you have 10k+ labeled examples.
- 3. Sample 1% of classifications through a frontier model weekly to detect drift in label quality.
- 4. For very high volume (1M+/day) consider self-hosted DistilBERT or similar — at scale, traditional NLP can be 100× cheaper than LLMs.
Cost at different scales
| Scale | Deepseek Chat | Gpt 5 Mini | Gemini 2.5 Flash | Claude Haiku 4 5 |
|---|---|---|---|---|
| Small inbox (5k/day) | $8.67 | $11.40 | $13.91 | $38.85 |
| Baseline (50k/day) | $86.73 | $114 | $139 | $389 |
| Enterprise (500k/day) | $867 | $1140 | $1391 | $3885 |
| Platform-scale (5M/day) | $8673 | $11.4k | $13.9k | $38.9k |
Try your own scenario
The numbers above use our best-guess assumptions. For your actual workflow, use the interactive calculator to plug in your real token volumes and quality requirements.
All cost figures are estimates based on publicly-listed pricing as of the data refresh date. Verify with the provider's official pricing page before making business decisions. Embedding costs, vector database costs, and infrastructure costs are not included unless explicitly noted.