Description
PromptSpend offers a comprehensive and transparent solution for estimating and comparing the costs associated with using Large Language Model (LLM) APIs. It provides a free, open-source platform that allows users to analyze potential expenses across 126 different models from 16 major providers, including GPT, Claude, Amazon, Google, and OpenAI. The platform's core strength lies in its daily re-verification of pricing data, ensuring that users always have access to the most current rates directly from vendor sources.
Read More
Users can interact with PromptSpend in two primary ways: by pasting their actual prompts or by using sliders to sketch out rough workload sizes. The tool then calculates and displays the estimated bill for each selected model side-by-side, updating costs live as text is typed or parameters are adjusted. This real-time feedback helps developers and businesses understand the financial implications of their AI features before deployment.
Beyond basic cost estimation, PromptSpend incorporates advanced assumptions to provide more realistic forecasts. It accounts for factors like prompt caching, using each provider's published cached and cache-write rates, and applies full price where such rates are not available. For chat applications with stable system prompts, it allows for a 60% cache-hit assumption. The calculator also considers batch API discounts, typically offering around 50% off for workloads that can tolerate delays, and includes a reasoning-token multiplier to model hidden reasoning costs.
The platform is designed for transparency, showing exactly where each price was read—whether from the vendor's own page or a public price feed. It even flags discrepancies for review. PromptSpend is accessible as a web calculator and dedicated mobile applications for iPhone and Android, all free to use, with no accounts required and no ads. The mobile apps offer the same catalog, sources, and dates, with features like forecasting conversations, comparing up to four models, and seeing what factors influence the cost. It also offers optional price alerts by email without requiring an account and allows sharing results as readable estimates, comparisons, CSVs, or Estimate Receipts, ensuring user privacy by processing pasted text locally on the device.
- CategoryPrompt Engineering Tools
- Pricing ModelFree
- DeploymentCloud
- PlatformsWeb, iOS, Android
PromptSpend's Core Features
LLM API Cost Estimation
Compare 126 Models from 16 Providers
Daily Price Re-verification
Real-time Cost Updates
Prompt Input or Workload Sketching
Side-by-Side Model Cost Comparison
Advanced Cost Assumptions (Caching, Batch API)
Transparent Price Sourcing
Free and Open Source
No Account Required
No Ads
Mobile Applications (iPhone, Android)
Optional Email Price Alerts
Shareable Cost Estimates (CSV, Receipt)
Private by Design (Local Text Processing)
How to use PromptSpend?
Access the Calculator: Visit promptspend.com or download the app for iPhone/Android.
Input Your Workload: Paste your real prompt text or use sliders to sketch input/output token counts.
Select Models: Choose up to four LLM models from the catalog for comparison.
Review Costs: See live, side-by-side cost estimates for each selected model based on your input.
Adjust Assumptions: Modify advanced settings like cache-hit rates or batch API usage for more accurate forecasts.
Analyze Price Changes: Monitor historical price changes and new model additions from vendors.
Share Estimates: Export your cost estimates as a readable report, CSV, or Estimate Receipt.
PromptSpend's Use Cases
- LLM API Cost Comparison
- AI Feature Budgeting
- Workload Cost Forecasting
- Optimizing LLM Usage
- Developer Cost Planning
- Market Price Monitoring
- Chatbot Cost Analysis
- Educational Cost Insight
