PromptLayer vs SpacePrompts
PromptLayer
promptlayer.comSpacePrompts
spaceprompts.comSide by side
| Figure | PromptLayer | SpacePrompts |
|---|---|---|
| Price from | $49/mo | $5/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 4 | 3 |
| Spec score · Prompting Tool | 7.8 (#6) | 8.4 (#3) |
| Spec score · AI Prompt Management Software | 7.9 (#12) | 8.5 (#8) |
| Spec score · Prompt Management Software | 7.9 (#14) | 8.5 (#8) |
| Evaluation | Evaluations can be triggered on new prompt versions, through the API, or ad hoc in the UI, and include historical backtests and side-by-side model comparisons. | The Evaluator scores prompts, identifies weak areas, and offers guidance to improve them. |
| Integrations | The LangChain integration exports traces through OpenTelemetry and supports cost and latency analytics, searchable metadata, and turning traces into evaluation datasets. | The privacy policy lists Google, GitHub, and Microsoft as OAuth providers for account authentication. |
| Intended users | PromptLayer describes its platform as serving engineers and domain experts who build and improve AI products together. | The maker describes SpacePrompts as serving people and teams who work with AI, including designers, writers, marketers, and API automation users. |
| Product | PromptLayer combines a prompt registry and visual prompt CMS with LLM evaluations, observability, and agent tracing. | SpacePrompts is a prompt management platform for saving, organizing, running, versioning, and reusing AI prompts. |
| Support | The pricing comparison lists basic support for Free, Pro, and Team, and dedicated support for Enterprise. | The site directs users to a contact form and says replies typically arrive within 24 hours. |
Plans
In their own words
PromptLayer
PromptLayer combines a prompt registry and visual prompt CMS with evaluations, observability, and agent tracing for teams building AI products. Teams can visually edit, version, test, and deploy prompts without waiting for an application redeploy, allowing domain experts and non-technical stakeholders to work alongside engineers. Evaluations can run when prompt versions change, through the API, or on demand in the UI. They include historical backtests and side-by-side model comparisons. Tracking covers requests, traces, cost, latency, token usage, scores, and custom metadata, with OpenTelemetry span support. The OpenAI integration includes versioned prompts, release labels, request observability, evaluations, and model comparisons. Free, Pro, and Team are cloud-hosted in the US; Enterprise offers self-hosting on GCP, AWS, or Azure, EU cloud hosting, or single-tenant cloud hosting. PromptLayer states that it maintains SOC 2 Type 2, HIPAA, GDPR, and CCPA compliance. Free costs nothing, Pro costs $49 a month, and Team costs $500 a month. Enterprise pricing is custom.
SpacePrompts
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.