To-do lists built from goals, calendars and routines rather than typed by hand.
Best free Productivity & writing APIs
10 Productivity & writing APIs with a free plan, compared side by side on endpoints, latency and price.
Which one to pick
- AI email response generator — smart auto reply covers the most ground with 7 endpoints.
- AI planner & to-do API — smart tasks and habit coaching was updated most recently, on 2025-12-08.
- Past the free plan, AI daily task planner — smart to-do generator & schedule API is the cheapest at $9.99 a month.
Choosing between APIs in the same category usually comes down to four numbers: how much surface the API covers, how fast it answers, how reliably it stays up and what it costs once the free tier runs out. The table below puts those numbers next to each other so the comparison takes a minute rather than an afternoon of tab-switching.
Every service listed here has a plan that costs nothing and needs no card, so the shortlist can be tested before any of it is paid for.
Frequently asked questions
- How many free Productivity & writing APIs are listed here?
- This catalogue lists 10 Productivity & writing APIs, all with a plan that costs $0. The most used are AI daily task planner — smart to-do generator & schedule API, AI email response generator — smart auto reply, AI email writer — professional emails in seconds.
- Which free Productivity & writing API covers the most endpoints?
- AI email response generator — smart auto reply covers the most ground with 7 endpoints.
- What does the cheapest paid Productivity & writing plan cost?
- Past the free plan, AI daily task planner — smart to-do generator & schedule API is the cheapest at $9.99 a month.
- Are these Productivity & writing APIs really free?
- Yes. Every Productivity & writing API listed here has a plan that costs $0 a month and needs no card. Paid plans exist for higher volume and their prices are in the table above.
Best free Productivity & writing APIs
Ready-to-send replies for Gmail, Outlook, Yahoo and Office 365.
Personalised, professional email drafts from a short brief.
Job descriptions written with the industry keywords that make them findable.
Scheduling, task automation and habit coaching from one productivity endpoint.
Estimate what a project will cost and how long it will take.
Condense articles and documents into summaries and extracted key points.
Multilingual grammar correction that returns the corrected sentence, not just flags.
Generate ready-to-import n8n automation workflows from a description.
Grammar and punctuation fixes, summaries and diff between two text versions.