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Machine Learning · head to head

OpenAI API vs Perplexity

OpenAI API logo

OpenAI API

Machine Learning

Hosted API for OpenAI's language, embedding, image and audio models, billed per token

From
$0.15/per-million-tokens
Rated
-
Full reviewWebsite
Perplexity logo

Perplexity

AI

AI-powered answer engine with citations

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only Perplexity has a free tier, so it costs nothing to try first.
  • Each has a real cost: OpenAI API cost scales with tokens rather than with seats, so a successful feature's bill grows with its adoption, and an interface that lets users paste long documents has no natural ceiling on spend unless you build one yourself.; Perplexity context window has been stealthily reduced despite prior claims of 1-million-token capacity
  • They diverge on capability: OpenAI API covers Text and reasoning models, Perplexity covers Real-time web search.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which OpenAI API and Perplexity actually diverge.

Attributes where OpenAI API and Perplexity differ
AttributeOpenAI APIPerplexity
Starting price$0.15/per-million-tokensFree
Pricing modelusage-basedUnknown
Free tierNoYes
PlatformsApiWeb, iOS, Android, Comet (AI browser)
CategoryMachine LearningAI
Founded20152022

Identical on both: user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in OpenAI API

  • Text and reasoning models
  • Embeddings
  • Speech and audio
  • Image generation
  • Function calling
  • Structured outputs
  • Batch processing
  • Prompt caching

Only in Perplexity

  • Real-time web search
  • Source citations
  • Follow-up questions
  • File analysis
  • Browser extension
  • API access
  • Mobile apps
  • Web support

What people use each for

The jobs each tool is most often brought in to do.

OpenAI API

  • Adding summarisation, drafting or classification to an existing product where building a model would take longer than the product's whole roadmapnot Perplexity
  • Retrieval-augmented question answering over internal documents, using the embedding and generation models togethernot Perplexity
  • Extracting structured records from unstructured text, where schema-constrained output removes most of the parsing problemnot Perplexity
  • Prototyping a language feature quickly to find out whether it is worth the cost of a self-hosted alternative laternot Perplexity

Perplexity

  • ai tools managementnot OpenAI API
  • Workflow automationnot OpenAI API
  • Reportingnot OpenAI API

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

OpenAI API

  • Cost scales with tokens rather than with seats, so a successful feature's bill grows with its adoption, and an interface that lets users paste long documents has no natural ceiling on spend unless you build one yourself.
  • Models are deprecated on the vendor's timetable, and a fine-tuned model built on a retired base goes with it, so the tuning work and the data curation behind it must be redone rather than migrated.
  • Behaviour shifts between model versions in ways no test catches unless you wrote one, so prompts tuned over months against a particular snapshot can regress quietly on migration, which makes an evaluation suite a prerequisite rather than an improvement.
  • It cannot run inside your own network, so data residency requirements, air-gapped environments and contracts forbidding third-party processing rule it out regardless of the provider's own security posture.
  • You inherit its availability and its rate limits, so a provider incident is an outage in your product and a traffic spike can be throttled at precisely the moment the feature is proving itself.

Perplexity

  • Context window has been stealthily reduced despite prior claims of 1-million-token capacity
  • Citations sometimes point to irrelevant or overly general articles that do not support the stated claims
  • Weak performance on complex multi-step reasoning and deep logic compared to dedicated reasoning LLMs
  • Web crawler ignores robots.txt directives and scrapes content from sites that explicitly opted out
  • Pro subscription quotas and feature access quietly reduced without user notification

Pricing, plan by plan

OpenAI API

$0.15/per-million-tokens
  • GPT-4o mini$0.15/per-million-input-tokens
    • Fast
    • Affordable
  • GPT-4o$5/per-million-input-tokens
    • Multimodal
    • 128K context

Perplexity

Free
  • FreeFree
    • Unlimited basic searches
    • 3 Pro Searches per day
    • 1 Research query per month
  • Pro$20/month
    • Unlimited Pro Searches
    • Advanced AI models
    • All free features
  • Pro Annual$200/year
    • Unlimited Pro Searches
    • Advanced AI models
    • All free features
  • Max$200/month
    • Unlimited Pro Searches
    • Labs multi-agent orchestration
    • Perplexity Computer with 19 AI sub-agents

Which should you pick?

Choose OpenAI API if

  • You need text and reasoning models.
  • You work on Api.
  • You also want embeddings.
OpenAI API review

Choose Perplexity if

  • You need real-time web search.
  • You want to start without paying.
  • You work on Web, iOS, Android, Comet (AI browser).
  • You also want source citations.
Perplexity review

Questions people ask

Is OpenAI API or Perplexity better?
Neither clearly leads. OpenAI API starts at $0.15/per-million-tokens and Perplexity at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, OpenAI API or Perplexity?
Perplexity has a free tier; the other does not. Paid plans start at $0.15/per-million-tokens for OpenAI API and Free for Perplexity.
Does OpenAI API or Perplexity run on more platforms?
OpenAI API runs on Api. Perplexity runs on Web, iOS, Android, Comet (AI browser).
Can I use Perplexity for free?
Yes. Perplexity has a free tier, so you can try it without paying. OpenAI API starts at $0.15/per-million-tokens.
What is OpenAI API best used for?
OpenAI API is most often used for adding summarisation, drafting or classification to an existing product where building a model would take longer than the product's whole roadmap, retrieval-augmented question answering over internal documents, using the embedding and generation models together, extracting structured records from unstructured text, where schema-constrained output removes most of the parsing problem, prototyping a language feature quickly to find out whether it is worth the cost of a self-hosted alternative later. Of those, adding summarisation, drafting or classification to an existing product where building a model would take longer than the product's whole roadmap and retrieval-augmented question answering over internal documents, using the embedding and generation models together are not what Perplexity is typically brought in for.
What can OpenAI API do that Perplexity cannot?
OpenAI API covers Text and reasoning models, Embeddings, Speech and audio, Image generation. Perplexity covers Real-time web search, Source citations, Follow-up questions, File analysis.

Answered from the vendors’ own pages

OpenAI API: Is my data used to train the models?

API inputs and outputs are not used for training by default, which differs from the consumer product. Retention periods and enterprise terms change, so read the current data usage policy rather than trusting a summary.

Perplexity: Is Perplexity completely free?

Perplexity has a free tier with unlimited basic searches and 3 Pro Searches per day. Pro ($20/month or $200/year) and Max ($200/month) tiers unlock more advanced features like multi-model access and unrestricted queries.

Source
OpenAI API: Can I run these models on my own hardware?

No. The weights are not distributed. If self-hosting is a requirement, you are looking at open-weight models instead, with the operational and quality trade-offs that implies.

Perplexity: What is the difference between Pro and Max?

Pro provides access to advanced AI models like GPT-5.2, Claude Sonnet 4.5, and Gemini 3 Pro. Max adds Labs for multi-agent orchestration, Perplexity Computer with 19 specialized AI sub-agents, and 10,000 Computer credits per month.

Source
OpenAI API: How is it priced?

Per token, with input and output priced differently and each model priced differently. Batch processing and cached input prefixes reduce it. The practical consequence is that your bill is a function of prompt design, not just of request count.

Perplexity: Can I use Perplexity offline?

No. Perplexity requires an active internet connection for all searches. The full answer service is not available offline.

Source
OpenAI API: What is the difference from Azure OpenAI Service?

The same model family delivered by Microsoft under an Azure contract, with Azure identity, networking and regional controls, and a different release cadence for new models. Enterprises with an Azure agreement often choose it for procurement and data residency reasons rather than technical ones.

Perplexity: What platforms does Perplexity support?

Perplexity is available as a web application, iOS app, Android app, and as Comet, a dedicated AI browser for mobile (Android available, iOS in development).

Source
OpenAI API: How do I keep the cost under control?

Cap input length, cache repeated prefixes, route easy requests to smaller models, use the batch path where latency does not matter, and set per-user limits before launch rather than after the first surprising invoice.

Perplexity: How reliable are Perplexity's citations?

Citations are a key feature of Perplexity, but users report that citations sometimes point to irrelevant or overly general articles that don't directly support the claims made.

Source
Perplexity: Does Perplexity's context window match the advertised 1 million tokens?

Perplexity had promoted a 1-million-token context window, but users have reported stealth reductions in the actual context capacity without public announcement.

Source
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