Side by side
PromptLayer vs SpacePrompts
Both stand on prompting tool. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan APISelf-hostedWeb
PromptLayer brings prompt editing, evaluation, and operational monitoring into one workflow, with collaboration features for technical and non-technical contributors. The Free plan has defined prompt and playground limits, while larger teams can consider paid plans or Enterprise hosting options.
Visit PromptLayer Free plan APIExtensionWeb
Pick SpacePrompts if you want a place to manage prompt versions, test prompts, and use browser extensions or an API. Free has capped prompt and daily-use allowances; API access requires Pro or Team and has a per-key request limit.
Visit SpacePromptsThe facts
| PromptLayer | SpacePrompts | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | No |
| Runs on | API, Self-hosted, Web | API, Extension, Web |
| Lowest paid plan | Pro: $49 a month | Pro: $5 a month |
| Plans published | 4 | 3 |
| Maker | Not published | Not published |
| Website | promptlayer.com | spaceprompts.com |
| On prompting tool | #4 of 25 | #8 of 25 |
PromptLayer: what it does well
- Edit and deploy prompts without an application redeploy.
- Evaluations include historical backtests and model comparisons.
- Tracks cost, latency, token use, scores, and traces.
- Enterprise supports flexible hosting options.
- Free plan includes 5 users and 2.5k monthly requests.
What to know first
- Free includes only 10 prompts and 10 daily playground runs.
- Webhooks are limited to Team and Enterprise.
- Pro costs $49 a month.
- Team costs $500 a month.
SpacePrompts: what it does well
- Playground combines editing, variables, model selection, and prompt runs.
- Evaluator scores prompts and gives improvement guidance.
- Every save creates a version users can roll back.
- Browser extensions support Chrome, Edge, and Firefox.
- Team workspaces include shared prompts and role-based permissions.
What to know first
- Free limits prompts to 50 and caps daily AI actions.
- API access is limited to 60 requests per minute per key.
- Team plan supports up to five members.
Alternatives to PromptLayer Alternatives to SpacePrompts The whole list