Frequently Asked Questions

Litra.ai queries the OpenAlex academic database directly to retrieve papers. Unlike ChatGPT, which generates text, we fetch search results directly from real paper databases — so fabricated papers are never suggested. We also run link verification on every reference to confirm each paper exists.

Hybrid search combines keyword search with semantic search. Keyword search, like Google Scholar, matches exact terms, while semantic search finds papers with similar meaning or concepts. For example, a search for 'crop monitoring' would also discover papers about 'agricultural field observation' or 'farmland surveillance.' Litra.ai merges both approaches so you never miss relevant papers.

The papers suggested by Litra.ai are retrieved directly from the OpenAlex academic database, so only real papers are displayed. AI summaries, analysis, and research assistant responses are generated based on paper abstracts. They're useful for quickly grasping the big picture — for deeper understanding, we recommend reading the original papers directly.

Litra.ai accesses OpenAlex (280M+ papers). OpenAlex integrates over 50 data sources including arXiv and PubMed, covering 98.6% of PubMed and spanning a wide range of academic disciplines. Future integration with JALC (Japan Link Center) will improve access to Japanese-language papers.

Yes. OpenAlex includes some Japanese papers, though English papers are currently the majority. Litra.ai automatically translates your Japanese queries into English for searching, then displays results in Japanese. Future JALC integration will expand Japanese paper coverage.

Results typically stream in within 1-3 minutes. Results appear progressively during the search, so there's minimal perceived wait time. Compared to Gemini Deep Research or ChatGPT Deep Research (5-30 minutes), Litra.ai delivers results significantly faster.

The free tier gives you 3 credits (approximately 3 searches). GPT-4.1 mini is available. You can try the same features as paid plans — multilingual translation, AI analysis chat, and paper analysis. No credit card required.

Credits are the currency used to search papers on Litra.ai. Different AI models consume different amounts (GPT-4.1 mini: ~1 credit, Haiku 4.5: ~3 credits, Sonnet 4.5: ~9 credits per search).

Yes, unused credits roll over to the next month. The maximum balance is capped at 2x your monthly credits. For example, on the Standard plan (100 credits/month), you can hold up to 200 credits including carried-over amounts.

We accept credit cards (Visa, Mastercard, American Express, JCB). All transactions are securely processed through Stripe.

Yes. We support reimbursement-based payment for KAKENHI. After paying by credit card, a receipt is automatically issued that you can submit to your university's accounting department. The receipt does not include a company seal (inkan), but this is legally fine. If your university requires a seal, please contact us and we'll accommodate. Bank transfer (invoiced payments) is planned for the future.

Yes, you can cancel at any time. After cancellation, you can continue using the service until the end of your current billing period.

If you purchased an annual plan within the last 14 days, you can request a refund from your account page. The refund amount is prorated based on unused credits (refund = payment × remaining credits ÷ total credits). Monthly plans do not offer prorated refunds, but you can continue using the service until the end of the billing period. A processing fee (3.6%) may be deducted from refunds.