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Updated 4 September 2026 · Independent comparison

OpenEvidence vs Petal:
which should you use?

OpenEvidence and Petal, side by side. Find the one that fits what you need to do.

Find your best fit

The 30-second answer

OpenEvidence is built for search, research & academics. Petal a document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions.

Pricing, simplified

Start free. Upgrade when you need more.

2 of 2 have a free plan 0 of 2 prices re-read automatically · how we know No paid placement

The 30-second comparison

If you only read one section, make it this one. Rows where both sides say the same thing are left out — the point is where they differ. Where each row came from is listed underneath.

OpenEvidence and Petal side by side, with the better fit for each row.
CategoryOpenEvidencePetalBetter fit
What it's built forBuilt for clinical literature. Answers cite primary medical research, and it is free for verified clinicians.A document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions.OpenEvidence
Fit for search, research & academicsBuilt for thisStrong fitOpenEvidence
Free planYes. Free for verified clinicians, ad-supportedYes. Free, with 1GB of cloud storage, one seat and three guests. Support is included rather than priorityTie
Cheapest way to payNo paid tier — it is free.$4.25 a month.OpenEvidence
What the paid tiers costNo paid tier — it is free.
  • One person, from $4.25/month
  • Enterprise, priced on request
Tie
What to watch out forMedicine only, and access is gated behind clinician verification. No use for a history or engineering student.You have to commit to keeping documents in it for the value to appear. The individual tiers are separated by storage rather than by features, and the two cheapest are priced for .edu addresses — without one they cost around two thirds more.Tie
Who it is usually forresearchers, working professionalsresearchers, working professionals, studentsTie
Sources you can checkAnswers carry sources you can open and check.Answers arrive without sources attached.OpenEvidence
Made byOpenEvidence — Cambridge, US.Petal — Cambridge, US.Tie

OpenEvidence is ahead on 4 of the 9 rows compared, 3 of them about how well it does the job itself. That is a clear lead rather than a tiebreaker.

Overall pick

OpenEvidence

Built for clinical literature.

✓ The job is mainly search, research & academics ✓ Built for clinical literature. ✓ You would rather not take on a subscription at all ✓ You need sources you can open and check
Choose Petal instead if…

A document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions.

Petal is the better answer when the job is what it was built for rather than what the pick above does broadly.

✓ A document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions. ✓ You are among students ✓ Free, with 1GB of cloud storage, one seat and three guests. Support is included rather than priority ✓ It is aimed at researchers, working professionals, students

How we know

Every row that separated these two, and where it came from. Nothing here is a hands-on test — if a line rests on a vendor’s own pricing page, it says so and links it.

The 4 rows that decided this page, with the source for each.
RowFavoursWeightWhere it came from
What it's built forOpenEvidenceHow well it does the jobFrom this site’s own catalogue record for each product — compiled by hand, not imported. How a product gets listed
Fit for search, research & academicsOpenEvidenceHow well it does the jobBoth products are listed under search, research & academics in the catalogue, and this is the fit recorded against each listing. Everything listed under search, research & academics
Cheapest way to payOpenEvidenceEverything elseFrom each vendor’s own pricing page. Dates and pages are listed below.
Sources you can checkOpenEvidenceHow well it does the jobFrom this site’s own catalogue record for each product — compiled by hand, not imported. How a product gets listed

The prices

OpenEvidence. Read by hand on 4 September 2026, because OpenEvidence cannot be read automatically: Free for verified clinicians, no paid tier — nothing priced to watch openevidence.com/pricing

Petal. Read by hand on 4 September 2026, because Petal cannot be read automatically: Plans live at /resources/pricing, not /pricing, which 404s. Still drawn in JavaScript, so transcribed by hand; re-verify the same way. petal.org/resources/pricing

The ratings

The category these two share. Search, Research & Academics — both are listed there in the catalogue, and the fit recorded against each listing is a judgement made here, by hand.

The nine-category grid below. Derived from what each product is listed for, by one script, once per build — so the same pair always reads the same. It is a derivation, not a review.

What this is not

Neither product was run side by side to produce this page. Nobody was paid to appear on it and nothing here is ranked by commission.

To put the same question to both and read the answers yourself, run them side by side — that is a live test, and this is not.

Choose based on what you’re doing

All ten categories, including the ones where neither of these is the answer. These ratings are derived from what each product is listed for, not from running it — a rating here is a reading of the record, and the record is linked.

01

General-Purpose AI Assistants

Questions, brainstorming, explanations, everyday tasks, decision-making, general advice.

OpenEvidence
Not a good fit
Petal
Not a good fit
Best choice: Neither
02

Search, Research & Academics

Web research, deep research, books, academic papers, citations, news, fact-checking.

OpenEvidence
Built for this
Petal
Good fit
Best choice: OpenEvidence
03

Writing, Communication & Language

Emails, reports, essays, editing, summarizing, translation, presentations.

OpenEvidence
Not a good fit
Petal
Not a good fit
Best choice: Neither
04

Coding, Data & Technical Work

Programming, debugging, data analysis, spreadsheets, math, engineering, technical research.

OpenEvidence
Bad fit
Petal
Bad fit
Best choice: Neither
05

Business, Finance & Professional Work

Business strategy, investing, market research, legal, sales, HR, accounting, consulting.

OpenEvidence
Not a good fit
Petal
Not a good fit
Best choice: Neither
06

Image & Design

Image generation, photo editing, logos, graphics, product design, advertising creatives.

OpenEvidence
Bad fit
Petal
Bad fit
Best choice: Neither
07

Video

Video generation and editing, clipping, subtitles, avatars, animation and motion capture.

OpenEvidence
Bad fit
Petal
Bad fit
Best choice: Neither
08

Audio, Voice & Music

Voice generation, transcription, music, dubbing, sound cleanup and podcast production.

OpenEvidence
Bad fit
Petal
Bad fit
Best choice: Neither
09

Marketing & Content Creation

Social media, SEO, advertising, copywriting, content ideas, scripts, brand development.

OpenEvidence
Bad fit
Petal
Bad fit
Best choice: Neither
10

Productivity, Automation & Personal Life

AI agents, workflows, scheduling, meetings, organization, shopping, travel, personal finance.

OpenEvidence
Not a good fit
Petal
Not a good fit
Best choice: Neither
Pick OpenEvidence if

Built for clinical literature.

Cambridge, US
The job is mainly search, research & academics
Built for clinical literature.
You would rather not take on a subscription at all
You need sources you can open and check
Pick Petal if

A document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions.

Cambridge, US
A document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions.
You are among students
Free, with 1GB of cloud storage, one seat and three guests. Support is included rather than priority
It is aimed at researchers, working professionals, students

Pricing, simplified

The plans people actually compare, read from each vendor’s own page.

PricingSimple, up-to-date plan overview.
OpenEvidenceby OpenEvidence
Petalby Petal
Free version
OpenEvidence
Yes — Free plan availableFree for verified clinicians, ad-supported
Petal
Yes — Free plan availableFree, with 1GB of cloud storage, one seat and three guests. Support is included rather than
Individual plans
OpenEvidenceFree plan only
Petal
Plus $4.25 / month$2.55 / month (annual)
Advanced $8.49 / month (annual)
Premium $29.99 / month$25.49 / month (annual)
Teams Starter $59.99 / month$50.99 / month (annual)
Teams Pro $119.99 / month$101.99 / month (annual)
Business plans
OpenEvidenceNot sold to teams
PetalNot sold to teams
Enterprise
OpenEvidenceNot published
Petal
Custom pricingTeams Enterprise
View full details
OpenEvidenceView OpenEvidence pricing
PetalView Petal pricing
Interactive

Tell us what you use AI for

Pick your main job and the verdict below changes to match. Every answer is on the page already, so this works as a reader, not a lookup.

The verdict for that job
OpenEvidence
OpenEvidence. It is built for search, research & academics; Petal does it well without it being its focus; both have a free plan you can start on.
9 rows compared

Frequently asked questions

Is OpenEvidence or Petal better?

OpenEvidence is ahead on 4 of the 9 rows compared, 3 of them about how well it does the job itself. That is a clear lead rather than a tiebreaker. OpenEvidence is built for search, research & academics; Petal does it well without it being its focus; both have a free plan you can start on. OpenEvidence: Built for clinical literature. Answers cite primary medical research, and it is free for verified clinicians. Petal: A document library with AI built in rather than a chat window you paste into, so your sources stay organised between sessions.

Is OpenEvidence or Petal cheaper?

Only one of the two publishes a ladder we have verified, so a like-for-like comparison is not possible yet.

Do OpenEvidence and Petal both have free plans?

Yes. OpenEvidence: Free for verified clinicians, ad-supported. Petal: Free, with 1GB of cloud storage, one seat and three guests. Support is included rather than priority.

What should I watch out for?

OpenEvidence: Medicine only, and access is gated behind clinician verification. No use for a history or engineering student. Petal: You have to commit to keeping documents in it for the value to appear. The individual tiers are separated by storage rather than by features, and the two cheapest are priced for .edu addresses — without one they cost around two thirds more.

Read more

OpenEvidence

What it is for, who makes it, what it costs and what to use instead.

Petal

What it is for, who makes it, what it costs and what to use instead.

Best AI for Research

Web research, deep research, books, academic papers, citations, news, fact-checking.

How we compare AI tools
Every row is generated from the same record the rest of the site is built on, so this page cannot drift from what we say elsewhere. We separate winner, tie and depends rather than forcing each category into a ranking, and we drop rows where both sides say the same thing. A pick is only called an overall pick when it leads on rows about how well the tool does the job; a lead that rests on price or audience alone is labelled as one. Nothing here is a hands-on test — how we know lists the source and date behind every deciding row.