Travel eSIM vs Roaming Pass: Which Costs Less for Your Trip?
Compare travel data packages with your home carrier’s roaming pass using compatibility checks, charged-day rules and two fictional total-cost examples.
Source-checked pre-flight decisions
Check the rules before you pack
Compare the total cost of two London airport options, compare two fares, get a route-aware answer for airport liquids and laptops, calculate whether a power bank can fly, or check carry-on and checked-bag rules for commonly questioned items. Every tool shows its scope, conditions and official sources.
Trip-cost calculator
London Airport Total Cost
Compare fares, unavoidable extras, ground quotes and time for two London airport options.
Compare airport options →
Fare checker
Flight Fare Decision Checker
Compare the fares you already found and see which one is actually cheaper after the bags and seats you need.
Compare two fares →
Route checker
Airport Security Rules
Compare liquid, laptop and reusable-bottle rules across departure, connection and return checkpoints.
Check your airports →
Battery checker
Power Bank Flight Rules
Convert capacity to watt-hours and compare cabin, quantity, approval and onboard-use limits.
Check a power bank →
Packing checker
Can I Bring It?
See separate carry-on and checked-bag decisions for vapes, razors, medicine and other high-question items.
Check an item →
Why use a checker? Airport, airline and aviation rules can differ by checkpoint, carrier, item and date. PrismGist links the evidence and keeps uncertain cases conditional.
Latest source-checked guides
Airport Fast Track vs Priority Boarding: What Are You Actually Paying For?
Compare airport security Fast Track, airline priority boarding and arrivals passport control. Use a journey-stage matrix, purchase checklist and fictional party-cost example.
Your Carry-On Is Being Gate-Checked: What to Remove Before You Hand It Over
Gate-checking your carry-on? Use this handover checklist to remove cabin-only batteries, keep essentials accessible and confirm where to collect your bag.
Separate Tickets vs One Booking: Is a Self-Transfer Flight Worth the Saving?
Compare separate flight tickets with one journey using complete bag, seat and transfer costs, realistic time, a fictional example and a missed-connection checklist.
Airport Rules vs Airline Rules: Who Decides Bags, Liquids, Batteries and Security?
Separate airline bag allowances, airport screening and battery safety rules with a responsibility matrix, codeshare examples and a five-step checking process.
Do You Go Through Security Again on a Connecting Flight? A Route-by-Route Guide
Find out when a connection needs security again, with Heathrow, Schiphol and Seattle examples, checkpoint rules and a practical transfer checklist.
OpenAI Model Not Showing in ChatGPT or Codex? How Rollouts and Model Access Work
OpenAI model missing from ChatGPT or Codex? Check the product surface, plan, workspace access, rollout, desktop or CLI updates, and separate API availability.
GPT-6.1 Sol vs GPT-6 Astra for Codex: Which Should You Use?
Choose GPT-6 Astra for maximum Codex coding quality or GPT-6.1 Sol for complex work with efficiency pressure. Compare tasks, limits and real usage.
Manchester Airport Baggage Weight Limits: Which Rule Applies?
Flying from Manchester? Check your airline's cabin and checked-bag allowance, separate booked weight from per-bag caps, and avoid buying the wrong baggage.