Guide
Best AI Writing Tools for Agencies (2026)
By Red Kite Search Agency Created Updated 9 min read
Summary
Jasper is the best for on-brand marketing content; Claude is the best for long-form writing and shared projects; ChatGPT is the best flexible general assistant; Grammarly is the best polish layer. Prices and ratings were checked in October 2026 and change often.
What are the best AI writing tools for agencies in 2026?
Agencies use AI to draft, edit, and research faster, but the tools differ in what they are for. Some are general assistants, some are built around marketing and brand voice, and some polish writing in every app.
We compared four tools agencies evaluate most often. The right mix depends on how many clients you serve, how strict their brand voices are, and what your clients allow on data.
Our shortlist, in order: Jasper, Claude, ChatGPT, Grammarly. The table puts them side by side.
| Tool | Best for | Editorial score | Review-site ratings | Pricing |
|---|---|---|---|---|
| Jasper | Best for on-brand marketing content | 4.3 / 5 | G2 4.7 | 7-day free trial. Pro $59 per seat per month on annual billing ($69 monthly); Business is custom. |
| Claude | Best for long-form writing and shared projects | 4.4 / 5 | G2 4.6 | Free plan. Pro $17 a month on annual billing ($20 monthly); Max from $100 a month. Team Standard $20 and Premium $100 per user per month on annual billing; Enterprise is $20 per seat plus usage. |
| ChatGPT | Best flexible general assistant | 4.4 / 5 | G2 4.6 | Free plan. Go $8, Plus $20 and Pro from $100 a month for individuals. Business Standard seats are $20 per user per month on annual billing ($25 monthly); Enterprise is custom. |
| Grammarly | Best polish layer | 4.3 / 5 | G2 4.7 | Free plan. Pro is $12 a month with a 7-day free trial (billing period not stated); Enterprise is quoted. |
How did we choose the best AI writing tools?
We included tools with public pricing, substantial review-site evidence, and common use among agencies. Pricing and features come from each vendor page, and ratings come from G2.
We looked closely at data terms, since client content is sensitive. Scores reflect fit for agencies producing content for several clients.
What we looked for
- Job: drafting, brand-led generation, or checking.
- Brand controls: voices, knowledge, and style guides.
- Team plans, seats, and admin controls.
- Data terms: training policy and compliance evidence.
- Free plan or trial availability.
- Public evidence: review-site ratings and review counts.
Is Jasper a good AI writing tool for agencies?
Best for on-brand marketing content: Jasper offers Brand Voices, Knowledge, and audiences built in, with SOC 2 Type II, SAML SSO on Business, and a no-training promise. Pro is one seat and Business is custom priced.
Jasper is an AI platform for marketing content with a Canvas workspace, marketing agents, Brand Voices, Knowledge assets, audiences, and an API on higher plans. It sells a Pro plan per seat with a 7-day free trial and a custom Business plan.
Who it suits: Agencies that produce on-brand marketing content for several clients and want brand voices and shared knowledge built in.
Jasper pros
- Pro costs $59 per seat per month on annual billing, with a 7-day free trial.
- Brand Voices, Knowledge assets and audiences keep output on brand.
- SOC 2 Type II, GDPR, CCPA and PCI compliance, with SAML SSO and SCIM on Business.
- Jasper states it does not use customer data to train models.
Jasper cons
- Pro is one seat with 2 Brand Voices, 5 Knowledge assets and 3 audiences.
- Business is custom priced, and API access is Business only.
- Mobile apps and the named underlying models were not stated.
- A dedicated agency plan was not stated, although you can create multiple projects per client.
Is Claude a good AI writing tool for agencies?
Best for long-form writing and shared projects: Claude offers Projects shared across a Team plan, SSO, no training on content by default on Team, and SOC 2 Type 2 and ISO 27001. Usage is capped and SCIM is Enterprise only.
Claude is Anthropic's AI assistant, with Projects, Artifacts, connectors and Claude Code, available on web, iOS, Android and desktop. It has Free, Pro and Max individual plans and Team and Enterprise plans with admin controls and shared projects.
Who it suits: Agencies that want an AI assistant for long-form writing, research and analysis with shared projects for a team.
Claude pros
- A free plan, with Pro at $17 a month on annual billing ($20 monthly).
- Team Standard seats cost $20 per user per month on annual billing, with SSO, shared projects and central billing.
- No model training on Team and Enterprise content by default.
- SOC 2 Type 2 and ISO 27001 for Team and Enterprise; Projects, Artifacts and connectors on every plan.
Claude cons
- Free, Pro and Max list model training as opt-out.
- Usage is capped by a rolling five-hour window and weekly limits, and Max costs $100 or $200 a month.
- SCIM, audit logs and a HIPAA-ready offering are Enterprise only, which needs 20 seats plus usage at API rates.
- GDPR and data residency detail were not stated; US-only inference costs 1.1x on the API.
Is ChatGPT a good AI writing tool for agencies?
Best flexible general assistant: ChatGPT offers a free plan, a Business workspace with connectors and SAML SSO, SOC 2 Type 2, and no training on business data by default. It has no built-in brand-voice structure.
ChatGPT is OpenAI's general AI assistant for drafting, editing, research, images, voice and custom GPTs. It has Free, Go, Plus and Pro individual plans and Business and Enterprise workspace plans with admin controls and connectors.
Who it suits: Agencies that want a general-purpose AI assistant for drafting, research, ideation and analysis across a whole team.
ChatGPT pros
- A free plan, Go at $8 a month and Plus at $20 a month.
- Business gives Standard seats for $20 per user per month on annual billing, with SAML SSO and connectors for Google Workspace, Slack, GitHub and Microsoft 365.
- No training on business data by default, and SOC 2 Type 2 for Business and Enterprise.
- Custom GPTs can be built and shared inside a workspace, with desktop, web and mobile access.
ChatGPT cons
- Usage on the free and low-cost plans is limited, and Pro starts at $100 a month.
- Business Premium seats cost $100 per user per month on annual billing.
- ISO 27001, HIPAA and a Business data residency option were not stated; data residency is Enterprise only.
- It is a general assistant, not a tool built around brand voice or content workflow.
Is Grammarly a good AI writing tool for agencies?
Best polish layer: Grammarly checks writing in every app with a free plan, plagiarism and AI-text detection on Pro, and a SOC 2 Type 2 report. It does not draft from scratch and its Pro billing period was unclear.
Grammarly checks spelling, grammar, tone and clarity wherever you write, with rewrite and generation features, plagiarism and AI-text detection, and style guides and brand tones for teams. It has a free plan, a Pro plan and an Enterprise plan sold through Superhuman Go.
Who it suits: Agencies whose writers, account managers and strategists need consistent, error-free copy and email across every tool.
Grammarly pros
- A free plan with 100 AI prompts a month.
- Pro adds sentence rewrites, tone adjustment, plagiarism and AI-text detection and 2,000 AI prompts, for $12 a month with a 7-day trial.
- Browser extension, Windows and Mac desktop apps, and iPhone, iPad and Android apps.
- SOC 2 Type 2 report, and Grammarly says it does not sell uploaded content.
Grammarly cons
- The Pro billing period was not stated on the page.
- Style guides and brand tones are 1 each on Pro and unlimited on Enterprise.
- SAML SSO and dedicated support are Enterprise only.
- ISO 27001, GDPR and HIPAA were not stated on the pages checked.
How much do the best AI writing tools cost?
Plans differ. Jasper and the team plans of ChatGPT and Claude charge per seat, Grammarly charges per user with an Enterprise tier for teams, and Claude and ChatGPT cap usage on lower plans. Add the team plan you need to your real seat count.
| Tool | Plan | Price | What stands out |
|---|---|---|---|
| Jasper | Pro | $59 per seat per month (annual billing); $69 monthly | 1 seat; Canvas; marketing agents; 2 Brand Voices; 5 Knowledge assets; 3 audiences |
| Jasper | Business | Custom | Unlimited Brand Voices and Knowledge; agents for GEO, translations and research; no-code agent builder; API; admin controls and Groups; priority support |
| Claude | Free | $0 per month (monthly billing) | Chat on all platforms, Projects up to 5, Artifacts, connectors, memory |
| Claude | Pro | $17 per month (annual billing); $20 monthly | More usage, Claude Code, Research, Projects, Claude in Chrome and Microsoft 365 |
| Claude | Max | $100 per month (monthly billing) | From; 5x or 20x Pro usage, priority access, $100 to $200 a month in API credits |
| Claude | Team Standard | $20 per month (annual billing); $25 monthly | Shared projects, SSO, central billing, admin controls for connectors, no training by default |
| Claude | Team Premium | $100 per month (annual billing); $125 monthly | 5x Standard usage |
| Claude | Enterprise | $20 per seat plus usage | 20-seat minimum; SCIM, audit logs, compliance API, custom retention, IP allowlisting, HIPAA-ready offering |
| ChatGPT | Free | $0 per month (monthly billing) | Unlimited text chats with limited uploads, images, voice and deep research |
| ChatGPT | Go | $8 per month (monthly billing) | More messages, uploads, images, voice and longer memory |
| ChatGPT | Plus | $20 per month (monthly billing) | Advanced reasoning, projects, scheduled tasks, custom GPTs, expanded deep research |
| ChatGPT | Pro | $100 per month (monthly billing) | From; three usage tiers, pro reasoning, maximum deep research and memory |
| ChatGPT | Business Standard | $20 per month (annual billing); $25 monthly | Workspace seat; SAML SSO, MFA, connectors, centralized billing, usage analytics |
| ChatGPT | Business Premium | $100 per month (annual billing); $125 monthly | 5x Standard usage, no 5-hour limit |
| ChatGPT | Enterprise | Custom | SCIM, Enterprise Key Management, data residency in ten regions, custom retention, 24/7 priority support and SLAs |
| Grammarly | Free | $0 per month (monthly billing) | Spelling and grammar, tone detection, 100 AI prompts |
| Grammarly | Pro | $12 per month (monthly billing) | Sentence rewrites, tone adjustment, plagiarism and AI-text detection, 2,000 AI prompts, 1 style guide and brand tone |
| Grammarly | Enterprise | Contact sales | Unlimited style guides and brand tones, SAML SSO, dedicated support, BYOK encryption, custom roles, data loss prevention |
What do reviewers say about these AI writing tools?
G2 evidence is strong for all four. Grammarly has the largest base, Jasper has the highest score on a mid-size base, and Claude has a smaller but positive base. Scores are close, so test on real briefs.
| Tool | Source | Rating | Number of reviews |
|---|---|---|---|
| Jasper | G2 | 4.7 / 5 | 1,317 |
| Claude | G2 | 4.6 / 5 | 496 |
| ChatGPT | G2 | 4.6 / 5 | 3,108 |
| Grammarly | G2 | 4.7 / 5 | 14,081 |
Reviewer themes for Jasper
- G2 shows Jasper at 4.7 from 1,317 reviews.
- Reviewers praise persona-specific messaging.
Reviewer themes for Claude
- G2 shows Claude at 4.6 from 496 reviews.
- Reviewers praise its context handling and ease of use.
Reviewer themes for ChatGPT
- G2 shows ChatGPT at 4.6 from 3,108 reviews.
- Reviewers value its versatility across many writing and analysis tasks.
Reviewer themes for Grammarly
- G2 shows Grammarly at 4.7 from 14,081 reviews.
- Reviewers value fast, reliable corrections across many apps.
How do you choose the right AI writing tool for your agency?
Start by deciding whether you need brand-led generation, a general assistant, or a checker. Brand-led work points to Jasper, general work to ChatGPT or Claude, and polish to Grammarly.
Whichever you choose, review client data terms before you paste material in, and build a human review step into your process.
A quick decision guide
- On-brand marketing content for many clients: Jasper.
- Long-form writing and shared projects: Claude.
- A flexible assistant with connectors: ChatGPT.
- Clean copy in every app: Grammarly.
- An SEO-led approach: see the SEO guides.
Frequently asked questions
- What is the best AI writing tool for agencies?
- Jasper for on-brand content, Claude or ChatGPT for general assistance, and Grammarly for polishing.
- Which tool is cheapest?
- Grammarly, ChatGPT, and Claude all have free plans.
- Which tools train on business data?
- Jasper, ChatGPT, and Claude state no training on business data by default, and Grammarly offers an opt-out setting.
- Which tool has built-in brand voices?
- Jasper.
- How were the tools rated?
- Ratings come from G2, and the editorial scores are our own judgement of fit for agencies.
Sources
Prices, plan limits, and ratings were gathered in October 2026 from:
- Jasper pricing page
- Claude pricing page
- ChatGPT pricing page
- Grammarly pricing page
- G2