# DeepSeek vs Grammarly

> DeepSeek: Free AI chat app and low-cost API running DeepSeek's open-weights V4 models
> Grammarly: AI writing assistant that corrects, rewrites and tone-checks your text across every app

- DeepSeek profile: https://finderatlas.com/tools/deepseek
- Grammarly profile: https://finderatlas.com/tools/grammarly
- Comparison page: https://finderatlas.com/compare/deepseek-vs-grammarly
- Last reviewed: October 2026

## Verdict

DeepSeek and Grammarly are both AI Assistants tools. DeepSeek scores higher in FinderAtlas's editorial review (8.8 vs 8.2 out of 10). Both have a free plan or trial. Only Grammarly is available on Chrome Extension and Firefox Extension.

### Choose DeepSeek if

- You want a tool built for Low-cost API integration.
- Web chat and mobile apps are free.
- API output costs from $0.60 per 1M tokens (Flash, off-peak), well below most frontier providers.

### Choose Grammarly if

- You want a tool built for polishing emails and documents in real time across many apps, keeping tone and style consistent across a team.
- Works across desktop, browser, Office, Google Docs and mobile keyboards, so suggestions follow you between apps.
- Free plan covers core grammar, spelling and tone visibility with 100 AI prompts per month.

## Pricing

| | DeepSeek | Grammarly |
| --- | --- | --- |
| Pricing model | Freemium | Freemium |
| Free plan or trial | Yes | Yes |
| Starting price | $0 | $0 |

## Features

| Feature | DeepSeek | Grammarly |
| --- | --- | --- |
| V4 model family | Yes | Not listed |
| Thinking mode | Yes | Not listed |
| Open weights | Yes | Not listed |
| OpenAI and Anthropic compatible API | Yes | Not listed |
| Tool calls and JSON output | Yes | Not listed |
| Search and Fetch APIs | Yes | Not listed |
| Agent tool integrations | Yes | Not listed |
| DeepSeek Harness | Yes | Not listed |
| Vision on Flash | Yes | Not listed |
| Citation Tools | Not listed | Yes |
| Style Guides and Brand Tones | Not listed | Yes |
| Cross-App Availability | Not listed | Yes |
| Enterprise Security Controls | Not listed | Yes |
| Grammar and Mistake Correction | Not listed | Yes |
| Tone Detection and Adjustment | Not listed | Yes |
| Full-Sentence and Paragraph Rewrites | Not listed | Yes |
| AI Detector and Humanizer | Not listed | Yes |
| Plagiarism Checker | Not listed | Yes |

## Platforms

| Platform | DeepSeek | Grammarly |
| --- | --- | --- |
| Web | Yes | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| iOS | Yes | Yes |
| Android | Yes | Yes |
| API | Yes | Yes |
| Browser Extension | No | No |
| Chrome Extension | No | Yes |
| Firefox Extension | No | Yes |

## DeepSeek strengths

- Web chat and mobile apps are free
- API output costs from $0.60 per 1M tokens (Flash, off-peak), well below most frontier providers
- Open weights for V4 and earlier models on Hugging Face
- 1M-token context and 384K max output on both API models
- API works with both OpenAI and Anthropic SDKs and several coding agents

## DeepSeek limitations

- Peak-hour API rates are double the off-peak rates on weekday mornings UTC
- deepseek-v4-pro does not support vision input
- No image generation
- Data is processed by a company based in China, which some organizations cannot accept

## Grammarly strengths

- Works across desktop, browser, Office, Google Docs and mobile keyboards, so suggestions follow you between apps.
- Free plan covers core grammar, spelling and tone visibility with 100 AI prompts per month.
- Pro adds tone adjustment, full-sentence rewrites, plagiarism and AI-text detection in a single subscription.
- Team features include style guides, brand tones, analytics and user groups; Enterprise adds SSO, SCIM and audit logs.
- Public REST APIs exist for analytics, licence management, writing score and detection.

## Grammarly limitations

- Monthly billing for Pro is $30, versus $12 per month on annual billing, so month-to-month use costs 2.5 times as much.
- Third-party tests of the AI Detector report notable false-positive rates (figures range from 14.2% to 34% across sources), so it is unreliable as proof.
- An App Store reviewer criticizes the iOS keyboard setup for pushing users to grant broad access.
- Experienced writers on forums report turning off many suggestions; advanced features are gated behind Pro.

## FAQ

**Is DeepSeek better than Grammarly?**

It depends on your workflow. DeepSeek is built for Low-cost API integration. Grammarly is built for polishing emails and documents in real time across many apps, keeping tone and style consistent across a team.

**What are the key feature differences between DeepSeek and Grammarly?**

DeepSeek: Free AI chat app and low-cost API running DeepSeek's open-weights V4 models. Grammarly: AI writing assistant that corrects, rewrites and tone-checks your text across every app.

**Does DeepSeek or Grammarly have a free plan?**

Yes, both do. DeepSeek is freemium and Grammarly is freemium, and each has a free plan or trial.

**Which is cheaper, DeepSeek or Grammarly?**

Both can be used for free. Paid plans differ in limits and features, so compare the tiers in the pricing table above.