Flask
Lightweight Python framework for web application development
- Vendor
- Pallets
- Also known as
- flask
Available worldwide
What is Flask?
A Python-based web framework that emphasizes simple setup while scaling to support complex, production-grade applications
Flask pricing
We don't have Flask's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.
What Flask does
The capabilities that matter for web frameworks, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.
- Rendering model
- Server-side
- File-based routing
- ✗
- Language
- Python
- Server components
- -
- Streaming SSR
- ✓
- Built-in API / backend routes
- ✓
- First-class TypeScript
- ✗
- Fast refresh / HMR
- ✓
- Edge runtime support
- -
Platform & deployment
Independently observed- CLI
- Web
Security & compliance
Known vulnerabilities: 5 (1 in the last 12 months), max severity HIGH sourcea count reflects scale & disclosure, not quality
Flask FAQ
Common questions about Flask, answered from independent, dated evidence.
What is Flask?
A Python web framework that makes it straightforward for developers to start building web applications, while maintaining the capability to handle large and sophisticated projects. It is indexed under Web Frameworks.
Is Flask free to use?
Flask is open source, so it can be self-hosted and used at no licence cost. It is released under the BSD-3-Clause licence. Pricing changes often, so verify at source before relying on it.
What platforms does Flask support?
Flask supports the web and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.
Is Flask open source?
Yes. Flask is published under the BSD-3-Clause licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.
Source: https://github.com/pallets/flask
Flask alternatives
Other web frameworks we track, ranked by the same independent score.
- Next.jsReact-based framework for complete web application developmenthigh · 76%
- FastAPIA Python web framework for building high-performance APIs quickly and easilymedium · 69%
- Nuxthigh · 77%
- ExpressA lightweight Node.js framework for building web applications without imposing strict architectural constraintshigh · 77%
- NestJShigh · 76%
- DjangoA web framework for rapid development of production-ready applicationsmedium · 70%
Compare Flask
Side by side against other web frameworks, attribute by attribute, with a source on every value.
The vioscaleAI score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Flask, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Dependent projects | 85 | 0.08 | 6.8 | ✓ |
| Capabilities | 75 | 0.08 | 6.2 | ✓ |
| Release cadence | 65 | 0.07 | 4.4 | ✓ |
| Development activity | 34 | 0.12 | 4.1 | ✓ |
| Security score | 71 | 0.05 | 3.8 | ✓ |
| Stars | 92 | 0.03 | 3.0 | ✓ |
| Integrations | 0 | 0.05 | 0.0 | - |
| Security posture | 0 | 0.09 | 0.0 | - |
| Package downloads | 0 | 0.17 | 0.0 | - |
| Developer Q&A activity | 0 | 0.08 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 11 | mediumsource · 2026-09-07 · 65% |
Adoption
Content
| Attribute | Value | Evidence |
|---|---|---|
| Faq | 4 items | mediumsource · 2026-09-10 · 69% |
Features
| Attribute | Value | Evidence |
|---|---|---|
| Capabilities | Language: Python · Rendering: ssr · Api routes: Yes · Hot reload: Yes · File routing: No · Streaming ssr: Yes | mediumsource · 2026-10-05 · 60% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | Python | highsource · 2026-10-05 · 90% |
License
| Attribute | Value | Evidence |
|---|---|---|
| Spdx | BSD-3-Clause | highsource · 2026-10-05 · 95% |
Market
| Attribute | Value | Evidence |
|---|---|---|
| Availability | PrimaryMarkets: … · AvailabilityScope: global · AvailableCountries: … · NotAvailableCountries: … | highsource · 2026-08-16 · 75% |
Pricing
Release
Reliability
| Attribute | Value | Evidence |
|---|---|---|
| Status page | Yes | mediumsource · 2026-10-05 · 60% |
Security
Is Flask the right choice for you?
Tell us the job, the constraints and what you weigh most, and we will rank Flask against the rest of the web frameworks we index, using the same dated evidence weighted your way.
Free to run, no account needed to start. How the evaluation works
Is this your product?
This profile was built from public sources without asking you. You can take the badge below and use it anywhere, and you can claim the profile to correct anything we got wrong. Both are free, and neither moves Flask up or down: nobody can buy rank here, including you.
Take the badge
Live, always current, and free to use on your own site. It shows Flask's independent score and links back to this profile.
<a href="https://www.vioscale.ai/software/flask" target="_blank" rel="noopener">
<img src="https://www.vioscale.ai/badge/software/flask.svg" alt="Flask, verified on vioscaleAI" width="330" height="76" loading="lazy" />
</a>Markdown, for a README →
[](https://www.vioscale.ai/software/flask)Claim the profile
Verify you control the domain, then point us at the pages that state the facts about Flask and add your own description and media. Free, and it does not change the score.
- Correct anything wrong, with evidence
- Point our crawler at the pages that matter
- Write your own description and add media
Not the owner? How vendor profiles work