Overview

Petal is an academic research assistant that brings PDF organization, study comparison, AI tools, and citation management together. It suits researchers and student teams who want one workspace for reading and references. Its breadth is appealing, but the free plan’s storage and citation-export limits make it a constrained way to judge the full workflow.

Key features

Petal’s research library stores PDFs and organizes them with collections, metadata, and tags. Shared workspaces support group projects, co-authored papers, and reviews, making it more useful to collaborative research than a standalone citation generator. The free tier’s 1 GB of storage, two collections, and three annotations per document could feel restrictive for a growing library.

Its AI tools cover translation, summaries, explanations, key-point extraction, question and search-term suggestions, and conversational AI. Petal also describes its research assistant as helping narrow literature reviews and compare studies. These capabilities bring discovery and document work into the same product, though AI credits are capped on every plan described here.

For references, Petal supports lookup by DOI, PMID, ArXivID, ISBN, ISSN, and EAN, as well as metadata capture from URLs. It can copy citations or export them as BibTeX or Word, and its citation generator supports over 10,000 styles according to the product description. The plan details give a different count—9,000 styles—so the precise count is not consistent. Free excludes citation export, an important gap for anyone who needs to move references into a manuscript.

Web importer add-ins are offered for Chrome, Firefox, and Safari, and a Word add-in inserts references and generates bibliographies. PDF annotation and team collaboration round out a workflow aimed at research rather than citation formatting alone. Petal says it generally responds to support requests within 30 minutes. Its privacy policy describes encryption and access controls, says user information is primarily stored in Oregon, and notes that the company was seeking ISO 27001 certification when that policy took effect.

Pricing

Petal uses a freemium model. Prices below are monthly amounts as stated; paid-plan pages also show different .edu and non-.edu prices, so check the applicable rate before choosing.

Free — 0.00 USD per month: 1 GB storage, one seat, three guests, 400 AI credits, two collections, and three annotations per document. It is a useful starting point for a small personal library, but citation export is excluded.
Plus — 2.55 USD per month: 2 GB storage, one seat, three guests, 400 AI credits per month, and unlimited collections and annotations. Multi-document chat and AI Create are not included. The page also gives prices of $2.99 with an .edu account and $4.99 otherwise; the pricing note describes paid access as starting at $4.99/user/mo (annual).
Advanced — 8.49 USD per month: 10 GB storage, one seat, three guests, 1,200 AI credits per month, unlimited collections and annotations, and priority support. The page also gives $9.99 with an .edu account and $13.99 otherwise. This tier is better suited to heavier individual use, but it still has one seat.
Premium — 25.49 USD per month: 25 GB storage, one seat, three guests, 2,000 AI credits per month, unlimited collections and annotations, and priority support. It raises the storage and AI ceilings but does not add seats.

Across the plans, collaboration is limited by the one-seat allowance and three guests shown for each tier. Plus keeps the same 400-credit allowance as Free, so its clearest gains are storage and removal of collection and annotation caps—not more AI use. No trial terms are given.

Platforms

Petal is available on the web and as a browser extension, with importer add-ins for Chrome, Firefox, and Safari and a Word add-in. It has no mobile apps, so it is a poor fit for anyone who expects a dedicated phone or tablet workflow.

Who it's for

Petal is best for academics, research groups, and students managing PDFs, literature reviews, and citations in one place. Its shared workspaces and institute-oriented enterprise offering suit collaborative research; the single-seat plan allowances mean teams should assess whether the guest model fits their working pattern. Readers seeking a simple citation tool, or a mobile-first reference manager, should look elsewhere.

Pros and cons

Pro: PDF library, AI research tools, collaboration, and citation features share one academic workflow, reducing the need to split those tasks across separate tools.
Pro: Broad reference lookup and Word integration help move citations from source discovery into bibliographies.
Con: Free has just 1 GB storage and no citation export, limiting its usefulness for a substantial library or finished writing workflow.
Con: Every described plan has one seat, and Petal offers no mobile apps.
Con: The published citation-style counts differ between the product description and plan details.

Alternatives

Choose NevaScholar Citation Generator if a free, no-sign-up web citation generator with 7,000+ styles is enough. Yomu AI Citation Generator offers a free web citation workflow with 15+ styles, DOI, URL, or title lookup, and bibliography and in-text formats. AllCitations is a free web option with 30+ styles, no citation limits, and no account requirement. CitePlex offers unlimited generation and copying across 11 styles on its free tier, alongside monthly save and project caps. Cytado is a freemium alternative with API, extension, and web platforms. Paperpal is another freemium option with extension and web platforms. AutoCaret Citation Generator offers a free tier with 20 credits and DOCX export. Citation Generator Canada is a free web tool with AI-powered metadata lookup and DOCX and TXT export.

For broader comparison, browse AI Citation Generators, Citation Management Software, Citation Generator Tools, or Reference Management Software.

Verdict

Petal is a strong fit for academic users who want PDF organization, AI-assisted literature work, shared projects, and citation management under one roof. Its main advantage is that connected research workflow; its main drawback is that storage, credits, export, seats, and mobile access put meaningful limits on who can rely on it. Choose it if those integrated tools matter more than a generous free tier or mobile access; otherwise, a focused citation tool may be the better match.

	Petal	Wren
Free plan	Yes	Yes
Free trial	No	No
Paid from	$2.55/mo	Free
Open source	No	No
Platforms	extension, Web	api, extension, macOS
Free plan	Yes	Yes
Paid from	4.99 /user/mo	—
PDF annotation	Yes	Yes
Browser capture	—	Yes

Petal vs Wren

Petal

Wren