ProofHound vs SpacePrompts

ProofHound is a prompt-optimization platform for LLM classification work, available through an API, self-hosted deployment, or the web. It examines error cases, iterates prompts, validates outputs, and provides controlled deployment and rollback. Dataset uploads accept CSV, TSV, JSONL, JSON arrays, and ZIP files, with field mapping in the interface. Optimization can target overall accuracy or category measures such as recall for high-risk categories and precision for error-prone classes. Immutable prompt versions retain variable configurations, output rules, and differences between revisions. Experiment records include datasets, model configurations, sample judgments, and overall and category metrics. Release controls include gray traffic, A/B testing, full rollout, and one-click rollback. Connections include the web UI, webhooks, API tokens, and MCP. Customers supply their own model provider, and ProofHound says model calls are not charged. A free plan is listed at free, while self-hosted open source is also free.

SpacePrompts is a prompt management platform for people and teams working with AI. It runs on the web, through an API, and with Chrome, Edge, and Firefox extensions. Users can save, organize, run, version, and reuse prompts. The Playground combines an editor, variables, model selection, and immediate runs. An Evaluator scores prompts, highlights weak areas, and gives improvement guidance. Every save creates a version that can be restored later. The prompt manager extension can turn highlighted webpage text into a prompt. Its token counter supports OpenAI, Claude, Gemini, and DeepSeek models, showing token counts and estimated costs. Pro and Team plans provide API access, limited to 60 requests per minute per key. Team workspaces add shared libraries, collaborative editing, and role permissions for up to five members. Free includes 50 prompts and daily usage limits; Pro is $5 a month billed annually, and Team is $9 a month billed annually.